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C语言作业答案(下)

第六章1

逆序输出输入的整数

#include <stdio.h>


int main ()
{
  int n;
  scanf("%d", &n);


  int num [n];


  for (int i = 0; i < n; i++) {
    scanf("%d", &num [i]);
  }


  int mask = 1;


  for (int j = n - 1; j >= 0; j--) {
    if (mask == 1) {
      printf("%d", num [j]);
      mask = 0;
    }else {
      printf(" %d", num [j]);
    }
  }


  return 0;


}

统计各大写字母的个数

#include <stdio.h>


int main ()
{
  char s[10000];
  scanf("%[^\n]", s);


  int cnt[26] = {0};


  for (int i = 0; s[i] != '\0'; i++) {
    if (s[i] >= 'A' && s[i] <= 'Z') {
      cnt[s[i] - 'A']++;
    }
  }


  for (int i = 0; i < 26; i++) {
    printf("%c(%d)", 'A' + i, cnt[i]);
    if ((i + 1) % 5 == 0) {
      printf("\n");
    }
  }


  return 0;


}

输出斐波那契数列的前n项

#include <stdio.h>


int main ()
{
  int n;
  scanf("%d", &n);


  int num [n];


  for (int i = 0; i < n; i++) {
    if (i == 0 || i == 1) {
      num [i] = 1;
    }else {
      num [i] = num [i - 1] + num [i - 2];
    }
  }


  int mask = 1;


  for(int j = 0; j < n; j++) {
    if (mask % 5 == 0) {
      if (mask == n) {
        printf("%10d", num [j]);
      }else {
        printf("%10d\n", num [j]);
        mask++;
      }
    }else {
      printf("%10d", num [j]);
      mask++;
    }
  }


  return 0;


}

约瑟夫问题

#include <stdio.h>


int main()
{
  int n, m, s;
  scanf("%d %d %d", &n, &m, &s);


  int num[n + 1];
  num[0] = 0;


  for (int i = 1; i <= n; i++) {
    num[i] = i;
  }


  int i = s;
  int t = n;


  while (t > 0) {
    int cnt = 0;
    while (cnt < m) {
      if (num[i] != 0) {
        cnt++;
      }


      if (cnt < m) {
        i++;
        if (i > n) {
          i = 1;
        }
      }
    }
    printf("%3d", num[i]);
    num[i] = 0;
    t--;


    do {
      i++;
      if (i > n) {
        i = 1;
      }
    }while (num[i] == 0 && t > 0);


  }


  return 0;


}

奇数阶幻方问题

#include <stdio.h>


int main ()
{
  int n;
  scanf("%d", &n);


  int s[n][n];


  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      s[i][j] = 0;
    }
  }


  int i = 0;
  int j = (n - 1) / 2;


  for (int k = 1; k <= n * n; k++) {
    s[i][j] = k;
    int I = i;
    int J = j;
    i -= 1;
    j += 1;


    if (i < 0) {
      i = n - 1;
    }
    if (j > n - 1) {
      j = 0;
    }
    if (s[i][j] != 0) {
      i = I + 1;
      j = J;
    }


  }


  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      printf("%4d", s[i][j]);
      if (j == n - 1) {
        printf("\n");
      }
    }
  }


  return 0;
}

统计学生的总分以及各课程的平均分

#include <stdio.h>


int main ()
{
  int n, m;
  scanf("%d %d", &n, &m);


  char name[n][100];
  int grade[n][m];


  int sum[n];


  for (int i = 0; i < n; i++) {
    sum[i] = 0;
  }


  for (int i = 0; i < n; i++) {
    scanf("%s", name[i]);
    for (int j = 0; j < m; j++) {
      scanf("%d", &grade[i][j]);
      sum[i] += grade[i][j];
    }
  }


  for (int i = 0; i < n; i++) {
    printf("%-8s", name[i]);
    printf("%6d", sum[i]);
    for (int j = 0; j < m; j++) {
      printf("%6d", grade[i][j]);
    }
    printf("\n");
  }


  double aver[m];


  for (int i = 0; i < m; i++) {
    aver[i] = 0;
  }


  for (int i = 0; i < m; i++) {
    for (int j = 0; j < n; j++) {
      aver[i] += grade[j][i];
    }
    aver[i] /= n;
  }


  printf("average score:");


  for (int i = 0; i < m; i++) {
    printf("%6.1f", aver[i]);
   }


  return 0;


}

统计学生成绩的最高最低分以及超过平均分的人数

#include <stdio.h>


int main ()
{


  int n;
  scanf("%d", &n);


  int grade[n];
  double aver = 0;


  for (int i = 0; i < n; i++) {
    scanf("%d", &grade[i]);
    aver += grade[i];
  }


  aver /= n;


  int cnt = 0;


  for (int i = 0; i < n; i++) {
    if (grade[i] > aver) {
      cnt++;
    }
  }


  int min = grade[0];


  for (int i = 1; i < n; i++) {
    if (grade[i] < min) {
      min = grade[i];
    }
  }


  int max = grade[0];


  for (int i = 1; i < n; i++) {
    if (grade[i] > max) {
      max = grade[i];
    }
  }


  printf("%d %d %d", max, min, cnt);


  return 0;
}

进制转换

#include <stdio.h>


int main ()
{
  char str[100];


  int num = 0;
  int i = 0;
  char c;


  while ((c = getchar()) != '#') {
    if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F') || (c >= 'a' && c <= 'f')) {
      str[i++] = c;
      num *= 16;
      if (c >= '0' && c <= '9') {
                num += c - '0';
            }else if (c >= 'A' && c <= 'F') {
                num += c - 'A' + 10;
            }else if (c >= 'a' && c <= 'f') {
              num += c - 'a' + 10;
      }
    }
  }


  str[i] = '\0';


  printf("String:%s\n", str);
  printf("number=%d", num);


  return 0;


}

求最大字符串

#include <stdio.h>
#include <string.h>


int main ()
{
  int n;
  scanf("%d", &n);
  getchar();


  char str[n][100];


  for (int i = 0; i < n; i++) {
    gets(str[i]);
  }


  int maxI = 0;


  for (int i = 1; i < n; i++) {
    if (strcmp(str[i], str[maxI]) > 0) {
      maxI = i;
    }
  }


  printf("%s", str[maxI]);


  return 0;


}

字符串首尾相连

#include <stdio.h>
int main() {
    char str1[101],str2[101];
    int i,j;


    gets(str1);
    gets(str2);
  // Here is your code
    i = 0;
    while (str1[i] != '\0' && str1[i] != '\n') {
        i++;
    }
    str1[i] = '\0';


    j = 0;
  while (str2[j] != '\0' && str2[j] != '\n') {
        j++;
    }
    str2[j] = '\0';


  for (int k = 0; k < j; k++) {
        str1[i] = str2[k];
        i++;
    }
    str1[i] = '\0';


  puts(str1);
  return 0;
}

统计各数字出现的次数

#include <stdio.h>


int main ()
{
  char c;
  int num[10] = {0};


  while (c != '!'){
    scanf("%c", &c);
    if (c >= '0' && c <= '9') {
      num[c - '0']++;
    }
  }


  for (int i = 0; i < 10; i++) {
    if (i == 9) {
      printf("The character %d appears %d times", i, num[i]);
    }else {
      printf("The character %d appears %d times\n", i, num[i]);
    }
  }


  return 0;


}

找出二维数组中的最小元素

#include <stdio.h>


int main ()
{
  int m, n;
  scanf("%d %d", &m, &n);


  int a[m][n];


  for (int i = 0; i < m; i++) {
    for (int j = 0; j < n; j++) {
      scanf("%d", &a[i][j]);
    }
  }


  printf("before:\n");


  for (int i = 0; i < m; i++) {
    for (int j = 0; j < n; j++) {
      printf("%4d", a[i][j]);
    }
    printf("\n");
  }


  printf("after:\n");


  int min =a[0][0];


  int I = 0;
  int J = 0;


  for (int i = 0; i < m; i++) {
    for (int j = 0; j < n; j++) {
      if (a[i][j] < min) {
        min = a[i][j];
        I = i;
        J = j;
      }
    }
  }


  for (int j = 0; j < n; j++) {
    int t = a[m - 1][j];
    a[m - 1][j] = a[I][j];
    a[I][j] = t;
  }


  int mask = 0;


  for (int i = 0; i < m; i++) {
    for (int j = 0; j < n; j++) {
      printf("%4d", a[i][j]);
    }
    if (i != m - 1) {
      printf("\n");
    }
  }


  return 0;
}

矩阵转置

#include <stdio.h>


int main ()
{
  int n, m;
  scanf("%d %d", &n, &m);


  int a[n][m];


  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      scanf("%d", &a[i][j]);
    }
  }


  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (j == m - 1) {
        printf("%d", a[i][j]);
      }else {
        printf("%d ", a[i][j]);
      }
    }
    printf("\n");
  }


  int b[m][n];


  for (int i = 0; i < m; i++) {
    for (int j = 0; j < n; j++) {
      b[i][j] = a[j][i];
      if (j == n - 1) {
        printf("%d", b[i][j]);
      }else {
        printf("%d ", b[i][j]);
      }
    }
    printf("\n");
  }


  return 0;


}

二分查找

#include <stdio.h>


int main ()
{
  int n;
  scanf("%d", &n);


  int num[n];


  for (int i = 0; i < n; i++) {
    scanf("%d", &num[i]);
  }


  int res;
  scanf("%d", &res);


  int a = 0;
  int b = n - 1;


  int mask = 0;


  while (a <= b) {


    int mid = a + (b - a) / 2;


    if (num[mid] == res) {
      printf("%d", mid);
      mask = 1;
      break;
    }else if (num[mid] < res) {
      a = mid + 1;
    }else {
      b = mid - 1;
    }
  }


  if (mask == 0) {
    printf("Not found");
  }


  return 0;


}

冒泡排序

#include <stdio.h>


int main ()
{
  int n;
  scanf("%d", &n);


  int num[100];


  for (int i = 0; i < n; i++) {
    scanf("%d", &num[i]);
  }


  for (int i = 0; i < n - 1; i++) {
    for (int j = 0; j < n - 1 - i; j++) {
      if (num[j] > num[j + 1]) {
        int t = num[j];
        num[j] = num[j + 1];
        num[j + 1] = t;
      }
    }
  }


  for (int i = 0; i < n; i++) {
    printf("%d", num[i]);
    if (i != n - 1) {
      printf(" ");
    }
  }


  return 0;


}

第六章2

大写改小写

#include <stdio.h>


int main ()
{
  char ch;
  while (scanf("%c", &ch) != EOF && ch != '\n') {
    if (ch >= 'A' && ch <= 'Z') {
      ch += 32;
    }
    putchar(ch);
  }


  return 0;


}

串比较

#include <stdio.h>


int main ()
{
  char str1[101];
  gets(str1);


  char str2[101];
  gets(str2);


  int i = 0;


  while (str1[i] != '\0' && str2[i] != '\0' && str1[i] == str2[i]) {
    i++;
  }


  printf("%d", str1[i] - str2[i]);


  return 0;
}

串复制

#include <stdio.h>
int main() {
  char str1[101],str2[101];
  int i;
  gets(str1);
  // Please fill this blank
  for (i = 0; str1[i] != '\0'; i++) {
    str2[i] = str1[i];
  }
  str2[i] = '\0';


  puts(str2);
  return 0;
}

逆向输出字符串

#include <stdio.h>


int main ()
{
  char str1[101],str2[101];
  int i,j;
  gets(str1);
  // Please fill this blank
  int l = 0;
  while (str1[l] != '\0') {
    l++;
  }
  for (i = 0, j = l - 1; j >= 0; i++, j--) {
    str2[i] = str1[j];
  }


  str2[l] = '\0';


  puts(str2);
  return 0;
}

对方阵做统计处理

#include <stdio.h>


void Traverse(int n, int s[n][n])
{
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      scanf("%d", &s[i][j]);
    }
  }
}


int sumD(int n, int s[n][n])
{
  int sum = 0;


  for (int i = 0; i < n; i++) {
    sum += s[i][i];
  }


  for (int i = 0; i < n; i++) {
    sum += s[n - 1 - i][i];
  }


  if (n % 2 != 0) {
    sum -= s[(n - 1) / 2][(n - 1) / 2];
  }


  return sum;


}


int multiple(int n, int s[n][n])
{
  int m = 1;


  for (int i = 0; i < n; i += 2) {
    m *= s[i][i];
  }


  for (int j = 0; j < n; j += 2) {
    if ((n - 1 - j) % 2 == 0) {
      m *= s[n - 1 - j][j];
    }
  }


  return m;


}


int main ()
{
  int n;
  scanf("%d", &n);


  int s[n][n];
  Traverse(n, s);


  printf("%d %d\n", sumD(n, s), multiple(n,s));


  int p[n][n];


  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      p[j][n - 1 - i] = s[i][j];
    }
  }


  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      printf("%d", p[i][j]);
      if (j < n - 1) {
        printf(" ");
      }
    }
    if (i < n - 1) {
      printf("\n");
    }
  }


  return 0;


}

兔子和狐狸

#include <stdio.h>


int main ()
{
  int n, m;
  scanf("%d %d", &n, &m);


  int h[n + 1];


  for (int i = 0; i <= n; i++) {
    h[i] = 1;
  }


  h[0] = 0;
  h[1] = 0;


  int i = 2;
  int j = 1;
  int s = 1;


  while (s <= m * n) {
    j += i;
    s += i;
    i++;
    if (s > m * n) {
      break;
    }
    if (j > n) {
      j %= n;
      if (j == 0) {
        j = n;
      }
    }
    h[j] = 0;
  }


  int mask = 1;


  for (int i = 0; i <= n; i++) {
    if (h[i] == 1) {
      if (mask == 1) {
        printf("%d", i);
        mask = 0;
      }else {
        printf(" %d", i);
      }
    }
  }


  if (mask == 1) {
    printf("No choice");
  }


  return 0;


}

删除字符串中指定字符

#include <stdio.h>


int main ()
{
  char str[101];
  gets(str);


  char ch;
  scanf("%c", &ch);


  int j = 0;


  for (int i = 0; str[i] != '\0'; i++) {
    if (str[i] != ch) {
      str[j++] = str[i];
    }
  }
  str[j] = '\0';


  printf("%s", str);


  return 0;
}

奇偶数分开排序

#include <stdio.h>


void sorting (int num[], int n)
{
  for (int i = n - 1; i > 0; i--) {
    int tag = i;
    for (int j = i - 1; j >= 0; j--) {
      if (num[tag] < num[j]) {
        tag = j;
      }
    }
    int t = num[i];
    num[i] = num[tag];
    num[tag] = t;
  }
}


void print (int num[], int n)
{
  int mask = 1;


  for (int i = 0; i < n; i++) {
    if (mask == 1) {
      printf("%d", num[i]);
      mask = 0;
    }else {
      printf(" %d", num[i]);
    }
  }
}


int main ()
{
  int n;
  scanf("%d", &n);


  int num[n];


  for (int i = 0; i < n; i++) {
    scanf("%d", &num[i]);
  }


  int odd[n];
  int even[n];


  int cnt1 = 0;
  int cnt2 = 0;


  for (int i = 0; i < n; i++) {
    if (num[i] % 2 == 1) {
      odd[cnt1] = num[i];
      cnt1++;
    }else {
      even[cnt2] = num[i];
      cnt2++;
    }
  }


  sorting(odd, cnt1);
  sorting(even, cnt2);


  print(odd, cnt1);
  printf(" ");
  print(even, cnt2);


  return 0;


}

选择排序

#include <stdio.h>


int main ()
{
  int n;
  scanf("%d", &n);


  int num[n];


  for (int i = 0; i < n; i++) {
    scanf("%d", &num[i]);
  }


  for (int i = n - 1; i > 0; i--) {
    int tag = i;
    for (int j = i - 1; j >= 0; j--) {
      if (num[tag] < num[j]) {
        tag = j;
      }
    }
    int t = num[i];
    num[i] = num[tag];
    num[tag] = t;
  }


  for (int i = 0; i < n; i++) {
    printf("%d ", num[i]);
  }


  return 0;


}

杨辉三角形

#include <stdio.h>


int main() {
    int n;
    scanf("%d", &n);
    int a[31][31] = {0};


    // 构造杨辉三角
    for (int i = 0; i < n; i++) {
        a[i][0] = a[i][i] = 1;
        for (int j = 1; j < i; j++) {
            a[i][j] = a[i-1][j-1] + a[i-1][j];
        }
    }


    for (int i = 0; i < n; i++) {
        for (int j = 0; j <= i; j++) {
            printf("%10d", a[i][j]);
        }
        printf("\n");
    }
    return 0;
}

在有序数组中插入一个数

#include <stdio.h>


int main ()
{
  int n;
  scanf("%d", &n);


  int num[n + 1];


  for (int i = 0; i < n; i++) {
    scanf("%d", &num[i]);
  }


  int m;
  scanf("%d", &m);


  num[n] = m;


  for (int i = n - 1; i >= 0; i--) {
    if (num[i] > num[i + 1]) {
      int t = num[i + 1];
      num[i + 1] = num [i];
      num[i] = t;
    }else {
      break;
    }
  }


  int mask = 1;


  for (int i = 0; i <= n; i++) {
    if (mask == 1) {
      printf("%d", num[i]);
      mask = 0;
    }else {
      printf(" %d", num[i]);
    }
  }


  return 0;


}

筛法求素数

#include <stdio.h>


int main ()
{
  int n;
  scanf("%d", &n);


  int Prime[n + 1];


  for (int i = 2; i <= n; i++) {
    Prime[i] = 1;
  }


  for (int i = 2; i <= n; i++) {
    if (Prime[i] == 1) {
      for (int k = i * i; k <= n; k += i) {
        Prime[k] = 0;
      }
    }
  }


  int mask = 1;


  for (int i = 2; i <= n; i++) {
    if (Prime[i] != 0) {
      if (mask == 1) {
        printf("%d", i);
        mask = 0;
      }else {
        printf(" %d", i);
      }
    }
  }


  return 0;


}

最长对称子串

#include <stdio.h>


int main ()
{
  char s[1001];
  gets(s);


  int length_I = 1;


  for (int i = 1; s[i] != '\0'; i++) {


    int length_i = 1;


    for (int j = 1; s[i + j] == s[i - j] && i - j >= 0; j++) {
      length_i += 2;
    }


    if (length_i > length_I) {
      length_I = length_i;
    }


  }


  int length_J = 0;


  for (int i = 0; s[i] != '\0'; i++) {


    int length_j = 0;


    for (int j = 1; s[i + 1 - j] == s[i + j] && i + 1 - j >= 0; j++) {
      length_j += 2;
    }


    if (length_j > length_J) {
      length_J = length_j;
    }
  }


  if (length_J > length_I) {
    printf("%d", length_J);
  }else {
    printf("%d", length_I);
  }


  return 0;


}

装睡的人

#include <stdio.h>


int main() {
    int N;
    scanf("%d", &N);
    char name[4];
    int breath, pulse;


    for (int i = 0; i < N; i++) {
        scanf("%s %d %d", name, &breath, &pulse);
        if (breath < 15 || breath > 20 || pulse < 50 || pulse > 70) {
            printf("%s\n", name);
        }
    }
    return 0;
}

第六章3

个位数统计

#include <stdio.h>
#include <string.h>


int main() {
    char N[1005];
    int count[10] = {0};


    scanf("%s", N);


    for (int i = 0; i < strlen(N); i++) {
        int d = N[i] - '0';
        count[d]++;
    }


    for (int d = 0; d <= 9; d++) {
        if (count[d] > 0) {
            printf("%d:%d\n", d, count[d]);
        }
    }
    return 0;
}

找出不是两个数组共有的元素

#include <stdio.h>


void find(int m, int n, int a[m], int b[n], int s[42])
{
  int cnt = 0;


  for (int i = 0; i < m; i++) {


    int mask = 0;
    for (int j = 0; j < n; j++) {
      if (a[i] == b[j]) {
        mask = 1;
        break;
      }
    }
    if (mask == 0) {
      s[cnt++] = a[i];
    }
  }


  for (int i = 0; i < n; i++) {


    int mask = 0;
    for (int j = 0; j < m; j++) {
      if (b[i] == a[j]) {
        mask = 1;
        break;
      }
    }
    if (mask == 0) {
      s[cnt++] = b[i];
    }
  }
}


void printing (int a[42])
{
  int s[42];


  for (int i = 0; i < 42; i++) {
    s[i] = -1;
  }


  for (int i = 0; i < 42 && a[i] != -1; i++) {
    if (s[i] == -1) {
      printf("%d ", a[i]);
      for (int j = i; j < 42 && a[j] != -1; j++) {
        if (a[j] == a[i]) {
          s[j] = 0;
        }
      }
    }
  }
}


int main ()
{
  int n;
  scanf("%d", &n);


  int a[n];
  for (int i = 0; i < n; i++) {
    scanf("%d", &a[i]);
  }


  int m;
  scanf("%d", &m);


  int b[m];


  for (int i = 0; i < m; i++) {
    scanf("%d", &b[i]);
  }


  int s[42];


  for (int i = 0; i < 42; i++) {
    s[i] = -1;
  }


  find(n, m, a, b, s);


  printing(s);


  return 0;


}

字符串逆序

#include <stdio.h>
#include <string.h>


int main ()
{
  char a[81];


  fgets(a, sizeof(a), stdin);


  int length = strlen(a);


  int j = length - 1;
  int i = 0;


  while (i < j) {
    char b = a[i];
    a[i] = a[j];
    a[j] = b;
    i++;
    j--;
  }


  printf("%s", a);


  return 0;


}

找鞍点

#include <stdio.h>


int main() {
    int n;
    scanf("%d", &n);
    int a[6][6];


    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            scanf("%d", &a[i][j]);
        }
    }


    for (int i = 0; i < n; i++) {
        int rowMax = a[i][0];
        for (int j = 1; j < n; j++) {
            if (a[i][j] > rowMax) {
                rowMax = a[i][j];
            }
        }


        for (int j = 0; j < n; j++) {
            if (a[i][j] == rowMax) {
                int colMin = a[0][j];
                for (int k = 1; k < n; k++) {
                    if (a[k][j] < colMin) {
                        colMin = a[k][j];
                    }
                }
                if (a[i][j] == colMin) {
                    printf("%d %d\n", i, j);
                    return 0;
                }
            }
        }
    }


    printf("NONE\n");
    return 0;
}

求n以内最大的k个素数以及它们的和

#include <stdio.h>


void findPrime (int n, int Prime[])
{
  for (int i = 2; i <= n; i++) {
    Prime[i] = 1;
  }


  for (int i = 2; i * i <= n; i++) {
    if (Prime[i] == 1) {
      for (int k = i * i; k <= n; k += i) {
        Prime[k] = 0;
      }
    }
  }


  Prime[0] = 0;
  Prime[1] = 0;
}


int main ()
{
  int max, cnt;
  scanf("%d %d", &max, &cnt);


  int isPrime[10001];
  findPrime(max, isPrime);


  int sum = 0;
  int mask = 0;


  for (int i = max; i > 0 && mask < cnt; i--) {
    if (isPrime[i] == 1) {
      sum += i;
      if (mask == 0) {
        printf("%d", i);
      }else {
        printf("+%d", i);
      }
      mask++;
    }
  }


  printf("=%d", sum);


  return 0;
}

1234方阵

#include <stdio.h>


void printing (int n, int s[n][n])
{
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      printf("%d", s[i][j]);
      if (j < n - 1) {
        printf(" ");
      }
    }
    printf("\n");
  }
}


int main ()
{
  int n;
  scanf("%d", &n);


  int s[n][n];


  for (int i = 0; i < n; i++) {
    s[i][i] = 0;
  }


  for (int i = 0; i < n; i++) {
    s[n - 1 - i][i] = 0;
  }


  int cnt = n - 2;
  int k = cnt;
  int l = cnt;
  int J = 1;


  for (int i = 0; k > 0; i++) {
    l = k;
    int j = J;
    while (l > 0) {
      s[i][j] = 1;
      l--;
      j++;
    }
    k -= 2;
    J += 1;
  }


  cnt = n - 2;
  k = cnt;
  l = cnt;
  int I = 1;


  for (int j = 0; k > 0; j++) {
    l = k;
    int i = I;
    while (l > 0) {
      s[i][j] = 2;
      l--;
      i++;
    }
    k -= 2;
    I += 1;
  }


  cnt = n - 2;
  k = cnt;
  l = cnt;
  J = 1;


  for (int i = n - 1; k > 0; i--) {
    l = k;
    int j = J;
    while (l > 0) {
      s[i][j] = 3;
      l--;
      j++;
    }
    k -= 2;
    J += 1;
  }


  cnt = n - 2;
  k = cnt;
  l = cnt;
  I = 1;


  for (int j = n - 1; k > 0; j--) {
    l = k;
    int i = I;
    while (l > 0) {
      s[i][j] = 4;
      l--;
      i++;
    }
    k -= 2;
    I += 1;
  }


  printing(n, s);


  return 0;


}

心情查询

#include <stdio.h>


void Traverse1 (int n, int s[n])
{
  for (int i = 0; i < n; i++) {
    scanf("%d", &s[i]);
  }
}


void initialize_Traverse2 (int n, int s[n])
{
  for (int i = 0; i < n; i++) {
    s[i] = -1;
  }


  int i = 0;
  int j;


  while (i < n - 1 && scanf("%d", &j) == 1) {
    if (j < 0 || j > 23) {
      break;
    }else {
      s[i++] = j;
    }
  }
}


int main ()
{
  const int n = 24;


  int s[n];
  Traverse1(n, s);


  int hour[n + 1];
  initialize_Traverse2(n + 1, hour);


  int i = 0;


  while (i < n + 1 && hour[i] != -1) {


    if (s[hour[i]] > 50) {
      printf("%d Yes", s[hour[i]]);
    }else if (s[hour[i]] <= 50) {
      printf("%d No", s[hour[i]]);
    }


    if (s[hour[i + 1]] != -1) {
      printf("\n");
    }else {
      break;
    }
    i++;
  }


  return 0;


}

点赞

#include <stdio.h>


int main ()
{
  int n;
  scanf("%d", &n);


  int q[1001] = {0};


  for (int i = 0; i < n; i++) {
    int p;
    scanf("%d", &p);


    for (int j = 0; j < p; j++) {
      int k;
      scanf("%d", &k);
      q[k]++;
    }


  }


  int max = 1000;


  for (int i = 1000; i >= 0; i--) {
    if (q[i] > q[max]) {
      max = i;
    }
  }


  printf("%d %d", max, q[max]);


  return 0;
}

古风排版

#include <stdio.h>


int ceiling (double num)
{
  int i = (int)num;
  if (num > i) {
    return i + 1;
  }
  return i;
}




int main ()
{
  int n;
  scanf("%d", &n);
  getchar();


  char s[1001];
  gets(s);


  int len = 0;


  while (s[len] != '\0') {
    len++;
  }
  s[len] = '\0';


  int column = ceiling((double)len / n);


  char c[n][column];


  int k = 0;


  for (int j = column - 1; j >= 0; j--) {
    for (int i = 0; i < n; i++) {
      if (k < len) {
        c[i][j] = s[k++];
      } else {
        c[i][j] = ' ';
      }
    }
  }


  for (int i = 0; i < n; i++) {
    for (int j = 0; j < column; j++) {
      printf("%c", c[i][j]);
    }
    printf("\n");
  }


  return 0;


}

字符串A-B

#include <stdio.h>


int main ()
{
  char a[10001];
  gets(a);
  char b[10001];
  gets(b);


  int c[10001] = {0};


  int k = 0;


  for (int i = 0; a[i] != '\0'; i++) {
    for (int j = 0; b[j] != '\0'; j++) {
      if (b[j] == a[i] ) {
        c[k++] = i;
        break;
      }
    }
  }


  for (int i = 0; a[i] != '\0'; i++) {
    int mask = 1;
    for (int j = 0; j < k; j++) {
      if (i == c[j]) {
        mask = 0;
        break;
      }
    }
    if (mask == 1) {
      printf("%c", a[i]);
    }
  }


  return 0;
}

n个数字都不相同的年份

#include <stdio.h>


void initialize_years(int year, int years[4])
{
  for (int i = 0; i < 4; i++) {
    years[i] = 0;
  }


  int i = 3;


  while (year > 0 && i >= 0) {
    years[i] = year % 10;
    year /= 10;
    i--;
  }
}


int main ()
{
  int y;
  scanf("%d", &y);


  int s[4];


  initialize_years(y, s);


  int n;
  scanf("%d", &n);


  int cnt = 0;


  while (1) {
    int mask = 1;
    int num[10] = {0};
    for (int i = 0; i < 4; i++) {
      int j = 0;
      for ( ; j < 10; ) {
        if (s[i] == j) {
          num[j]++;
          break;
        }else {
          j++;
        }
      }
    }
    for (int k = 0; k < 10; k++) {
      if (n == 4) {
        if (num[k] != 0 && num[k] != 1) {
          mask = 0;
          break;
        }
      }else if (n == 3) {
        int cnt = 0;
        for (int l = 0; l < 10; l++) {
          if (num[l] == 2) {
            cnt++;
          }
        }
        if (cnt != 1) {
          mask = 0;
          break;
        }
      }else if (n == 2) {
        int tag = 0;
        for (int l = 0; l < 10; l++)
        if (num[l] == 0) {
          tag++;
        }
        if (tag != 8) {
          mask = 0;
          break;
        }
      }
    }
    if (mask == 0) {
      y += 1;
      cnt++;
      initialize_years(y, s);
    }else {
      break;
    }
  }


  printf("%d ", cnt);


  for (int i = 0; i < 4; i++) {
    printf("%d", s[i]);
  }


  return 0;


}

矩阵A乘以B

#include <stdio.h>


int main() {
    int Ra, Ca, Rb, Cb;
    int A[100][100], B[100][100], C[100][100];


    scanf("%d %d", &Ra, &Ca);
    for (int i = 0; i < Ra; i++) {
        for (int j = 0; j < Ca; j++) {
            scanf("%d", &A[i][j]);
        }
    }


    scanf("%d %d", &Rb, &Cb);
    for (int i = 0; i < Rb; i++) {
        for (int j = 0; j < Cb; j++) {
            scanf("%d", &B[i][j]);
        }
    }


    if (Ca != Rb) {
        printf("Error: %d != %d\n", Ca, Rb);
        return 0;
    }


    for (int i = 0; i < Ra; i++) {
        for (int j = 0; j < Cb; j++) {
            C[i][j] = 0;
            for (int k = 0; k < Ca; k++) {
                C[i][j] += A[i][k] * B[k][j];
            }
        }
    }


    printf("%d %d\n", Ra, Cb);
    for (int i = 0; i < Ra; i++) {
        for (int j = 0; j < Cb; j++) {
            if (j > 0) printf(" ");
            printf("%d", C[i][j]);
        }
        printf("\n");
    }


    return 0;
}

查验身份证

#include <stdio.h>


int main ()
{
  int s[17];
  int a[17] = {7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2};


  int i = 0;
  int sum = 0;


  while (i < 17 && scanf("%1d", &s[i]) == 1) {
    sum += s[i] *a[i];
    i++;
  }


  char b;
  scanf("%c", &b);


  sum %= 11;


  int z[11] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
  char m[11] = {'1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2'};


  char mask = '0';


  for (int i = 0; i < 11; i++) {
    if (sum == z[i]) {
      mask = m[i];
    }
  }


  if (mask == b) {
    printf("No problem");
  }else {
    printf("Incorrect");
  }


  return 0;
}

判断题的评判

#include <stdio.h>


int main ()
{
  int n;
  scanf("%d", &n);


  int AC[n];


  for (int i = 0; i < n; i++) {
    scanf("%d", &AC[i]);
  }


  int WA[n];


  int cnt = 0;


  for (int i = 0; i < n; i++) {
    scanf("%d", &WA[i]);
    if (WA[i] == AC[i]) {
      cnt++;
    }
  }


  double x;


  x = 1.0 * cnt / n;


  printf("%.2f%%", x * 100);


  return 0;
}

数组元素循环右移问题

#include <stdio.h>


void reverse(int a[], int l, int r) {
  while (l < r) {
    int t = a[l];
    a[l] = a[r];
    a[r] = t;
    l++;
    r--;
  }
}


int main ()
{
  int n, m;
  scanf("%d %d", &n, &m);
  m %= n;


  int s[n];
  for (int i = n - 1; i >= 0; i--) {
    scanf("%d", &s[i]);
  }


  reverse(s, 0, m - 1);
  reverse(s, m, n - 1);


  for (int i = 0; i < n; i++) {
    printf("%d ", s[i]);
  }


  return 0;


}

第七章

定义print函数，输出n个*

void print(int k)
{
  for (int i = 1; i <= k; i++)
    printf("*");
  printf("\n");
}

定义函数求π的近似值

double funpi(double e)
{
  double flag = 1, sum = 0;
  for (int i = 1;; i++)
  {
    double t = flag / (2 * i - 1);
    if (t < 0)
    {
      if (-t < e)
        break;
    }
    else
    {
      if (t < e)
        break;
    }
    sum += t;  //求和
    flag = -flag;  //正负反转
  }
  return sum;
}

设计函数计算并输出矩形的面积

void area(int a, int b)
{
    printf("%d", a * b);
}

定义函数prime，判定正整数n是否素数

#include <math.h>
int prime(int n)
{
  for (int i = 2; i <= sqrt(n); i++)
    if (n % i == 0)
      return 0;


  return 1;
}

设计函数实现冒泡排序

void sort(int a[], int n)
{
  for (int i = 0; i < n - 1; i++)  //一趟冒泡排序,把最小的数字放在最末尾
  {
    for (int j = 0; j < n - i - 1; j++)  //每经过一趟冒泡排序,需要检索的数字个数-1
    {
      if (a[j] < a[j + 1])  //如果左边的数字小于右边的数字,实现相邻两个数的交换
      {
        int t = a[j];
        a[j] = a[j + 1];
        a[j + 1] = t;
      }
    }
  }
}


void print(int a[], int n)
{
  for (int i = 0; i < n; i++)
  {
    if (i == 0)
      printf("%d", a[i]);
    else
      printf(" %d", a[i]);
  }
  printf("\n");
}

设计函数实现矩阵的转置

void convert(int arr1[][10], int arr2[][10], int x, int y)
{
  for (int i = 0; i < x; i++)
    for (int j = 0; j < y; j++)
      arr2[j][i] = arr1[i][j];  // 矩阵行列坐标互换
}


void print(int arr[][10], int x, int y)  //二维数组的行可以不初始化,列一定要初始化
{
  for (int i = 0; i < x; i++)  //控制行数
  {
    for (int j = 0; j < y; j++)  //控制列数
    {
      if (j == 0)
        printf("%d", arr[i][j]);
      else
        printf(" %d", arr[i][j]);
    }
    printf("\n");
  }
}

设计函数实现二分查找

int BinSearch(int a[], int n, int x)
{
  int left = 0;  //数组最左侧元素下标
  int right = n - 1;  //数组最右侧元素下标
  while (left <= right)
  {
    //int mid = (right + left) / 2;
    int mid = left + (right - left) / 2;  //防止数据过大，越界
    if (x < a[mid])
      left = mid + 1;
    else if (x > a[mid])
      right = mid - 1;
    else
      return mid;
  }
  return -1;
}

定义menu函数，输出菜单选项

void Menu()
{
  printf("       Menu\n");
  printf("  (1)--读取数据\n");
  printf("  (2)--数据计算\n");
  printf("  (3)--查找数据\n");
  printf("  (4)--输出数据\n");
  printf("  (0)--退出程序\n");
}

设计函数计算学生的平均成绩

double average(int a[], int n)
{
  double sum = 0;
  for (int i = 0; i < n; i++)
    sum = sum += a[i];
  return  sum / n;
}

设计递归函数模拟汉诺塔游戏

void move(int n, char a, char b, char c)
{
  if (n == 1)
    printf("%c-->%c\n", a, c);  //当只有一个盘子时,直接从起始柱移到目标柱
  else
  {
    move(n - 1, a, c, b);  //第一步:将n-1个盘子由a移动到b,注意此时起始柱是a,中转柱是c,目标柱是b;
    printf("%c-->%c\n", a, c);  //第二步:将第n个盘子从起始柱移到目标柱
    move(n - 1, b, a, c);  //第三步:将n-1个盘子由b移动到c,注意此时起始柱是b,中转柱是a,目标柱是c;
  }
}

设计递归函数计算Fibonacci数列的第n项

int fib(int n)
{
  if (n <= 1)
    return 1;
  else
    return fib(n - 1) + fib(n - 2);
}

设计递归函数计算组合

int fun(int m, int n)
{
  if (n == 0 || n == m)  //c(0,m)和c(m,m)都为1(特判)
    return 1;
  else
    return fun(m - 1, n - 1) + fun(m - 1, n);  //组合数公式 c(n,m)=c(n-1,m-1)+c(n-1,m)  m>=n
}

设计递归函数计算两个整数的最大公约数

int gcd(int m, int n)  //辗转相除法
{
    if (n == 0)
        return m;
    else
        return gcd(n, m % n);
}

设计递归函数计算n！

int fac(int n)
{
  if (n <= 1)
    return 1;
  else
    return n * fac(n - 1);
}

设计max函数，计算三个整数的最大值

int max(int a, int b, int c)
{
  if (a >= b && a >= c)
    return a;
  if (b >= a && b >= c)
    return b;
  if (c >= a && c >= b)
    return c;
}