C语言作业答案(上)

临近期末，打开oj，一笔没动，怎么办！

不用担心。这里有人经历过。为了不让更多的人经历如此磨难，现有答案供君参考。

若答案顺序与作业顺序不同，可联系笔者！

第一章

求圆的面积和周长

#include <stdio.h>

int main()
{
  double r;
  double s, c;
  const double K=3.140000;

  scanf("%lf", &r);

  s=K*r*r;
  c=2*K*r;

  printf("%lf\n%lf", s, c);

  return 0;
}

求2个整数的和

#include <stdio.h>

int main()
{
  int a, b;

  scanf("%d %d", &a, &b);

  int c=a+b;

  printf("%d",c);

  return 0;
}

输出2行信息

#include <stdio.h>

int main()
{
  printf("Programing is fun.\n");
  printf("Programing in language C is even more fun!");
}

Hello World!

#include <stdio.h>

int main()
{
  printf("Hello World!");

  return 0;
}

设计函数求2个整数的最大值

int max (int x, int y) {
    if (x >= y) {
        return x;
    } else {
        return y;
    }
}

求2个整数的最大值

#include <stdio.h>

int main()
{
  int a, b, max;

  scanf("%d %d", &a, &b);

  if (a>b) max=a;
  else max=b;

  printf("max=%d",max);

  return 0;
}

This is a C program

#include <stdio.h>

int main()
{
  printf("This is a C program");

  return 0;
}

第二章

猫是液体

#include <stdio.h>

int main ()
{
  int a, b, c;
  scanf("%d %d %d", &a, &b, &c);

  int v = a * b * c;

  printf("%d", v);

  return 0;
}

中英长度单位换算

#include <stdio.h>

int main()
{
  int cm, foot, inch;

  scanf("%d", &cm);

    int t=cm/30.48;

  double n=cm/30.48;

  foot=t;

  inch=(n-t)*12;

  printf("%d %d", foot, inch)  ;

  return 0;
}

打妖怪

#include <stdio.h>

int main()
{
  int a, b, c;

  scanf("%d %d", &a, &b);

  int rem=a%b;
  int t=a/b;

  if (rem==0)
     printf("%d", t);

  else
     printf("%d", t+1);

  return 0;

}

求整数均值

#include <stdio.h>

int main()
{
  int a, b, c, d;

  scanf("%d %d %d %d", &a, &b, &c, &d);

  int sum=a+b+c+d;
  double aver=(a+b+c+d)/4.00;

  printf("Sum = %d\nAverage = %.2f", sum, aver);

  return 0;
}

整数四则运算

#include <stdio.h>

int main()
{
  int a, b;

  scanf("%d %d", &a, &b);

  printf("%d + %d = %d\n", a, b, a+b);
  printf("%d - %d = %d\n", a, b, a-b);
  printf("%d * %d = %d\n", a, b, a*b);
  printf("%d / %d = %d", a, b, a/b);

  return 0;
}

分糖果

#include <stdio.h>

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

  int a = x / 3;
  x = a;
  y += a;
  z += a;

  int b = y / 3;
  x += b;
  y = b;
  z += b;

  int c = z / 3;
  x += c;
  y += c;
  z = c;

  printf("%d %d %d", x, y, z);

  return 0;
}

自由落体

#include <stdio.h>

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

  int h = 10 * t * t / 2;

  if (h > 2000) {
    printf("2000");
  }else {
    printf("%d", h);
  }

  return 0;
}

计算终止时间

#include <stdio.h>
#include <stdlib.h>

int main ()
{
    char str[4];
    double num;
    int a;

    scanf("%s %d", &str, &a);

    num = atof(str);

    int NUM = num;

    int min = NUM % 100;
    int hour = NUM / 100;

    int res = a + min;

    if (res >= 60) {
      int temp = res / 60;
      hour += temp;
      res -= temp * 60;
  }else if (res < 0) {
    res = -res;
    int temp = res / 60;
    hour -= temp + 1;
    res -= temp * 60;
    res = 60 - res;
  }

  if (res >= 60) {
      int temp = res / 60;
      hour += temp;
      res -= temp * 60;
    }

  printf("%d%02d", hour, res);

    return 0;
}

输出四位整数的各位数字

#include <stdio.h>

int main()
{
  int num;

  scanf("%d", &num);

  int a=num/1000,
      b=num/100-a*10,
      c=num/10-a*100-b*10,
      d=num-a*1000-b*100-c*10;

  printf("%d=%d+%d*10+%d*100+%d*1000", num, d, c, b, a);

  return 0;
}

两小时学完C语言

#include <stdio.h>

int main()
{
  int n, k ,m;

  scanf("%d %d %d", &n, &k, &m);

  int remain=n-k*m;

  printf("%d", remain);

  return 0;
}

计算图形面积

#include <stdio.h>

int main()
{
  int a, b;

  scanf("%d %d", &a, &b);

  int s=abs(50*a-50*b);

  printf("%d", s);

  return 0;
}

折扣

#include <stdio.h>

int main()
{
  int ori, dis;

  scanf("%d %d", &ori, &dis);

  double final=ori*dis/10.00;

  printf("%.2f", final);

  return 0;
}

标准体重和身高的对应关系

#include <stdio.h>

int main()
{
  int h=0;

  scanf("%d", &h);

  double m=(h-100)*0.9*2;

  printf("%.1f", m);

  return 0;
}

后天

#include <stdio.h>

int main()
{
  int D=0;

  scanf("%d", &D);

  D+=2;

  if(D>7) D-=7;

  printf("%d", D);

  return 0;
}

第三章

字母对应的ASCII 码

#include <stdio.h>

int main()
{
  char ch;

  scanf("%c", &ch);

  printf("%d", ch);

  return 0;
}

温度转换

#include <stdio.h>

int main()
{
  double f=0;

  scanf("%lf", &f);

  double c=5.0/9.0*(f-32);

  printf("%lf", c);

  return 0;
}

计算圆的周长

#include <stdio.h>

int main()
{
  double r;
  double K=3.14;

  scanf("%lf", &r);

    double c=2*K*r;

    printf("%lf", c);

    return 0;
}

求三位整数的逆序数

#include <stdio.h>

int main()
{
  int num = 0;
  int result = 0;
  int digital = 0;

  scanf("%d", &num);

  while (num > 0){
    digital = num % 10;
    result = result * 10 + digital;
    num /= 10;
  }

  printf("%03d", result);

  return 0;
}

求三角形面积

#include <stdio.h>
#include <math.h>

int main()
{
    double a, b, c;

    scanf("%lf %lf %lf", &a, &b, &c);

    double p = (a + b + c) / 2;

    double s = sqrt(p * (p - a) * (p - b) * (p - c));

    printf("%.2f", s);

    return 0;
}

计算浮点数相除的余数

#include <stdio.h>

int main()
{
  double a, b;

  scanf("%lf %lf", &a, &b);

  int k=0;
    double tag=0.0;
    double n=0.0;

    do{
      n=a-k*b;
      k++;
  }while (n>=0);

  double r=n+b;

  printf("%g", r);

  return 0;
}

年增长率

#include <stdio.h>
#include <math.h>

int main()
{
  int n;

  scanf("%d", &n);

  double x=pow(2.0, 1.0/n);

  double res=(x-1.0)*100;

  printf("%.2f%%", res);

  return 0;
}

快速求和

#include <stdio.h>

int main()
{
  int n;

  scanf("%d", &n);

  int tag;
  double s=0.0;

  for (tag=1; tag<=n; tag++){
    s+=1.0/(tag*(tag+1.0));
  }

  printf("%.5f", s);

  return 0;
}

混合类型数据格式化输入

#include <stdio.h>

int main()
{
  double a, b;
  int c;
  char d;

  scanf("%lf %d %c %lf", &a, &c, &d, &b);

  printf("%c %d %.2f %.2f", d, c, a, b);

  return 0;
}

定期存款

#include <stdio.h>

int main()
{
  double a, b;

  scanf("%lf %lf", &a, &b);

  double res1=a*b/100.0;

  double res2=res1+a;

  printf("%11.2f\n%11.2f\n%11.2f", a, res1, res2);

  return 0;
}

日期格式变化

#include <stdio.h>

int main()
{
  int m, d, y;

  scanf("%d-%d-%d", &m, &d, &y);

  printf("%02d-%02d-%02d", y, m, d);

  return 0;
}

水果店收款

#include <stdio.h>

int main()
{
  double a, b, c, d;

  scanf("%lf %lf %lf %lf,", &a, &b, &c, &d);

  double p=2.5*a+1.7*b+2*c+1.2*d;

  printf("%.2f", p);

  return 0;
}

计算房间面积

#include <stdio.h>

int main()
{
  double a, b;

  scanf("%lf\n%lf", &a, &b);

  double c=a*b;

  printf("the area of the room:%lf", c);

  return 0;
}

第四章

三天打鱼两天晒网

#include <stdio.h>

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

  int tag = n % 5;

  switch (tag) {
    case 1:
    case 2:
    case 3:
      printf("Fishing in day %d", n);
        break;

    default:
      printf("Drying in day %d", n);
  }

  return 0;

}

闰年

#include <stdio.h>

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

  int mask1 = yr%400;
  int lpyr = 0;

  int mask2 = yr%4;
  int mask3 = yr%100;

  if (mask1 == 0) {
    lpyr = 1;
  }else {
    if (mask2 == 0) {
      if (mask3 != 0 ){
        lpyr = 1;
      }
    }
  }

  if (lpyr == 1) {
    printf("%d is a leap year!", yr);
  }else {
    printf("%d isn't a leap year!", yr);
  }

  return 0;

}

三个整数排序

#include <stdio.h>

int main()
{
  int a, b, c;
  scanf("%d %d %d", &a, &b, &c);

  int num1, num2, num3;

  if (a > b) {
    if (a > c){
      num1 = a;
      if (b > c){
          num2 = b, num3 = c;
        }else {
          num2 = c, num3 = b;
            }
          }else {
          num1 = c, num2 = a, num3 = b;
      }

  }else{
    if (b > c){
      num1 = b;
      if (a > c){
        num2 = a, num3 = c;
      }else {
        num2 = c, num3 = a;
      }
    }else{
      num1 = c, num2 = b, num3 = a;
    }
  }

  printf("a=%d,b=%d,c=%d", num3, num2, num1);

  return 0;
}

判断水仙花数

#include <stdio.h>

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

  int a, b, c;
  a = num / 100;
  b = num / 10 - a * 10;
  c = num - a * 100 - b * 10;

  int A = 1;
  int B = 1;
  int C = 1;

  int cnt = 0;


  do {
    A *= a;
    B *= b;
    C *= c;

    cnt++;

  }while (cnt != 3);

  int res;
  res = A + B + C;

  if (res == num) {
    printf("YES");

  }else {
    printf("NO");
  }

  return 0;

}

计算奖金

#include <stdio.h>

int main()
{
  double p;
  scanf("%lf", &p);

  double bonus;

  if (p <= 100000) {
    bonus = p * 0.10;

  }else if (p > 100000 && p <= 200000) {
    bonus = 10000 + (p - 100000) * 0.075;

  }else if (p > 200000 && p <= 400000) {
    bonus = 17500 + (p - 200000) * 0.05;

  }else if (p > 400000 && p <= 600000) {
    bonus = 27500 + (p - 400000) * 0.03;

  }else if (p > 600000 && p <= 1000000) {
    bonus = 33500 + (p - 600000) * 0.015;

  }else if (p > 1000000) {
    bonus = 39500 + (p - 1000000) * 0.01;

  }//恶心

  printf("%.2f", bonus);

  return 0;
}

按公式计算y和z的值

#include <stdio.h>
#include <math.h>

int main()
{
  double x = 0.0;
  scanf ("%lf", &x);

  double y, z;

  if (x >= 1 && x < 2) {
    y = x * x + 1.0;
    z = 3.0 * x + 5.0;
  }else if (x >= 2 && x <= 2.5) {
    y = x * x + 1.0;
    z = 2.0 * sin(x) - 1.0;
  }else if (x > 2.5 && x < 3) {
    y = x * x - 1.0;
    z = 2.0 * sin (x) - 1.0;
  }else if (x >= 3 && x < 5) {
    y = x * x - 1.0;
    z = sqrt (1.0 + x * x);
  }else if (x >= 5 && x < 8) {
    y = x * x - 1.0;
    z = x * x - 2 * x + 5;
  }

  printf("%lf\n%lf", y, z);

  return 0;
}

24小时时间记法转12小时时间记法

#include <stdio.h>

int main()
{
  int hor, min, sec;
  scanf("%d %d %d", &hor, &min, &sec);

  if (hor >= 12) {
    printf("%d %d %d PM", hor-12, min, sec);
  }else {
    printf("%d %d %d AM", hor, min, sec);
  }

  return 0;

}

能否构成三角形

#include <stdio.h>

int main()
{
  int a, b, c;
  scanf("%d %d %d", &a, &b, &c);

  if (a+b > c && a+c > b && b+c > a) {
    printf("YES");
  }else {
    printf("NO");
  }

  return 0;
}

找出3个整数居中的整数

#include <stdio.h>

int main()
{
  int a, b, c;
  scanf("%d %d %d", &a, &b, &c);

  int res;

  if (a > b) {
    if (b > c) {
      res = b;
    }else if (a > c) {
      res = c;
    }else {
      res = a;
    }
  }else if (a > c) {
    res = a;
  }else if (b > c) {
    res = c;
  }else {
    res = b;
  }

  printf("%d", res);

  return 0;
}

学生成绩评定

#include <stdio.h>

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

  if (scr > 85) {
    printf("very good");
  }else if (scr <= 85 && scr >= 60) {
    printf("good");
  }else {
    printf("no good");
  }

  return 0;

}

求月份对应的英文名称及天数

#include <stdio.h>

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

  switch ( mth ) {
    case 1:
      printf("January,31");
      break;

    case 2:
      printf("February,28/29");
      break;

    case 3:
      printf("March,31");
      break;

    case 4:
            printf("April,30");
            break;

    case 5:
      printf("May,31");
      break;

    case 6:
      printf("June,30");
      break;

    case 7:
      printf("July,31");
      break;

    case 8:
      printf("August,31");
      break;

    case 9:
      printf("September,30");
      break;

    case 10:
      printf("October,31");
      break;

    case 11:
      printf("November,30");
      break;

    case 12:
      printf("December,31");
      break;

  }

  return 0;

}

百分制分数转换为等级

#include <stdio.h>

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

  int tag = scr;
  scr /= 10;

  switch ( scr ) {
    case 10:
    case 9:
      printf("score=%d,grade:A", tag);
      break;

    case 8:
      printf("score=%d,grade:B", tag);
      break;

    case 7:
      printf("score=%d,grade:C", tag);
      break;

    case 6:
      printf("score=%d,grade:D", tag);
      break;

      default:
      printf("score=%d,grade:E", tag);
      break;
  }

  return 0;
}

第五章1

求若干整数的最大值

#include <stdio.h>

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

  int max = 0;
  int cnt = 1;
  int num = 0;

  scanf("%d", &max);

  for (cnt = 1; cnt < n; cnt++) {
    scanf("%d", &num);
    if (num > max) {
      max = num;
    }
  }

    printf("%d", max);

  return 0;
}

n！

#include <stdio.h>

int main()
{
  int num = 0;
  int res = 1;
  int fac = 1;

  scanf("%d", &num);

  while (fac <= num){
    res *= fac;
    fac++;
  }

  printf ("%d!=%d", num, res);

  return 0;
}

最大公约数

#include <stdio.h>

int main()
{
  int num1, num2;
  scanf("%d %d", &num1, &num2);

  int mask = 0;

  while (num2 != 0) {
    mask = num1 % num2;
    num1 = num2;
    num2 = mask;
  }

  printf("%d", num1);

  return 0;
}//解决了1 2的公约数是1的问题

最小值和最大值

#include <stdio.h>

int main ()
{
  int n = 0;
  scanf("%d", &n);

  int first = 0;
  scanf("%d", &first);

  int max = first;
  int min = first;
  int num = 0;
  int cntmax = 1;
  int cntmin = 1;

  for (int cnt = 1; cnt < n; cnt++) {
    scanf("%d", &num);
    if (num > max) {
      max = num;
      cntmax = 1;
    }else if (num == max) {
      cntmax++;
    }
    if (num < min) {
      min = num;
      cntmin = 1;
    }else if (num == min) {
      cntmin++;
    }
  }

  printf("%d %d\n%d %d", min, cntmin, max, cntmax);

  return 0;
}

连续因子

#include <stdio.h>

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

    long long len = 0;
    long long ans = 0;

    for (long long i = 2; i * i <= n; i++) {
        long long temp = 1;
        long long k = i;
        while (temp * k <= n) {
            temp *= k;
            if (n % temp == 0 && k - i + 1 > len) {
                len = k - i + 1;
                ans = i;
            }
            k++;
        }
    }

    if (len == 0) {
        printf("1\n%lld\n", n);
    } else {
        printf("%lld\n", len);
        for (int i = 0; i < len; i++) {
            if (i > 0) printf("*");
            printf("%lld", ans + i);
        }
        printf("\n");
    }

    return 0;
}

打印沙漏

#include <stdio.h>

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

  int sum = -1;
  int i = 2;

  while (n - sum - i >= 0) {
    sum += i;
    i += 4;
  }

  int k = i;
  int j = 1;
  int u = 1;

  while (k > 2) {

  int t = k / 2;
  int j = u;

    while (t > 2) {
      if (t == 3) {
        printf("*\n");
      }else {
        printf("*");
      }
      t--;
    }

    while (j > 0 && k > 6) {
      printf(" ");
      j--;
    }

  k -= 4;
  u += 1;

  }

  k = i;
  u -= 3;
  int p = 3;
  int m = 3;

  while (u >= 0) {

    j = u;
     p = m;

    while (j > 0) {
      printf(" ");
      j--;
    }

    while (p > 0) {
      if (p == 1) {
        printf("*\n");
      }else {
        printf("*");
      }
      p--;
    }

    m += 2;
    u -= 1;
  }

  int difference = n - sum;

  printf("%d", difference);

  return 0;
}

念数字

#include <stdio.h>

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

    int mask = 1;
    int t = x;

    if (x < 0) {
      printf("fu ");
      x = - x;
      t = - t;
  }

  while (t > 9) {
      t /= 10;
      mask *= 10;
  }

  do {
    int d = x / mask;

    switch (d) {
      case 0:
        printf("ling");
        break;
      case 1:
        printf("yi");
        break;
      case 2:
        printf("er");
        break;
      case 3:
        printf("san");
        break;
      case 4:
        printf("si");
        break;
      case 5:
        printf("wu");
        break;
      case 6:
        printf("liu");
        break;
      case 7:
        printf("qi");
        break;
      case 8:
        printf("ba");
        break;
      case 9:
        printf("jiu");
        break;
    }

    x %= mask;
    mask /= 10;

    if (mask > 0) {
      printf(" ");
    }

  }while (mask > 0);

  return 0;
}

N个有理数求和

#include <stdio.h>
#include <stdlib.h>

#define ll long long

ll abss(ll x) { return x < 0 ? -x : x; }

ll gcd(ll a, ll b) {
    if (a < 0) a = -a;
    if (b < 0) b = -b;
    while (b != 0) {
        ll t = a % b;
        a = b;
        b = t;
    }
    return a;
}

int main() {
    int n;
    if (scanf("%d", &n) != 1) return 0;

    ll num = 0;
    ll den = 1;

    for (int i = 0; i < n; ++i) {
        ll a, b;
        scanf("%lld/%lld", &a, &b);

        ll g = gcd(den, b);
        ll den1 = den / g;
        ll b1 = b / g;

        ll new_num = num * b1 + a * den1;
        ll new_den = den * b1;

        ll g2 = gcd(abss(new_num), new_den);
        new_num /= g2;
        new_den /= g2;

        if (new_den < 0) { new_den = -new_den; new_num = -new_num; }

        num = new_num;
        den = new_den;
    }

    ll integer = num / den;
    ll remainder = num % den;

    if (remainder == 0) {
        printf("%lld", integer);
        putchar('\n');
    } else {
        if (integer != 0) {
            printf("%lld", integer);
            putchar(' ');
            printf("%lld", remainder);
            putchar('/');
            printf("%lld", den);
            putchar('\n');
        } else {
            printf("%lld", remainder);
            putchar('/');
            printf("%lld", den);
            putchar('\n');
        }
    }

    return 0;
}

画方块

#include <stdio.h>
#include <math.h>

int main()
{
  double n;
  char c;
  scanf("%lf %c", &n, &c);

  int cnt = 0;
  double mask = 0.0;
  int tag = round (n / 2);

  while (cnt <= n) {
    cnt++;
    printf("%c", c);
    if (cnt == n) {
      printf("\n");
      cnt = 0;
      mask ++;
      if (mask == tag) {
        break;
      }
    }
  }

  return 0;
}

守形数

#include <stdio.h>

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

  int tag = min;
  int mask = 10;
  int test = 0;
  int isfirst = 1;

  for (tag = min; tag <= max; tag++) {
    int t = tag * tag;
    int p = tag;
      mask = 1;
    while (p > 0) {
      p /= 10;
      mask *= 10;
    }
    int cur = t % mask;
    if (cur == tag) {
      if (isfirst == 1) {
        printf("%d", tag);
        test = 1;
        isfirst = 0;
      }else{
      printf(" %d", tag);
    }
  }
  }

  if (test == 0) {
    printf("No exist");
  }

  return 0;
}

含数字5且是3的倍数

#include <stdio.h>

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

  int i = m;
  int tag = 1;

  while (i <= n) {

    int j = 1;
    int k = i;

    int mask = 0;

    while (k > 0) {
      int num = k % 10;
      if (num == 5) {
        mask = 1;
        break;
      }else {
        k /= 10;
      }
    }

    if (i % 3 == 0 && mask == 1) {
      if (tag == 1) {
        printf("%d", i);
        tag = 0;
      }else {
        printf(" %d", i);
      }
    }

    i++;

  }

  if (tag == 1) {
    printf("No exist");
  }

  return 0;

}

小球自由落体

#include <stdio.h>

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

  int cnt = 0;
  double res = 0.0;
  double h = 100.0;
  int tag = 1;

  for (cnt = 0; cnt< n; cnt++) {
    if (tag == 1) {
      res += 100;
      tag = 0;
    }else {
      h /= 2;
        res += h*2;

    }
  }

  printf("%lf %lf", res, h/2);

    return 0;

}

鸡兔同笼

#include <stdio.h>

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

  int c = 0;
  int r = 0;
  int res = 0;

    for (r = 0; r<= h; r++) {
      c = h - r;
      if (4*r + 2* c == f) {
        res = 1;
        break;
    }
  }

  if (res == 1) {
    printf ("%d %d", c, r);
  }else {
    printf("Error");
  }

  return 0;

}

计算π的近似值

#include <stdio.h>

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

  int cnt = 0;
  double res = 0.0;
  int i = 1;
  int sign = 1;

  for (cnt = 0; cnt < 2*n; cnt++) {
    res += sign * 1.0 / i;
    i += 2;
    sign = -sign;
  }

  printf("%lf", res*4.0);

  return 0;
}

“韩信点兵”数

#include <stdio.h>

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

  int res = 0;
  int cnt = 0;
  int tag = 1;

  for (res = min; res <= max ; res++) {
    if (res % 3 == 2 && res % 5 == 3 && res % 7 == 4) {
                if ( tag == 1) {
                    printf("%d", res);
                    tag = 0;
                    cnt++;
                }else {
                cnt++;
                printf(" %d", res);
      }
    }

  }

  if (cnt == 0) {
    printf("total=0");
  }else {
    printf("\ntotal=%d", cnt);
    }

  return 0;
}

祖孙年龄

#include <stdio.h>

int main()
{
  int x, y1, y2, y3;
  scanf("%d %d %d %d", &x, &y1, &y2, &y3);

  int res = x - y1 - y2 - y3;

  if (res % 2 == 0) {
    printf("%d", res / 2 );
  }else {
    printf("%d", (res + 1) / 2 );
  }

  return 0;
}

输出Fibonacci数列的前n项

#include <stdio.h>

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

  int i = 1;
  int j = 0;
  int k;
  int cnt;
  int p = 1;

  for (cnt = 0; cnt < n; cnt++) {
    printf("%10d", i);
    if (p % 5 == 0 && p!= 0) {
      printf("\n");
    }
    k = i;
    i = j + i;
    j = k;
    p++;
  }

  return 0;
}

菱形图案

#include <stdio.h>

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

  n += 1;

  int cnt = 1;
  int CNT = 1;

  for (int s = n - 1; s > 0; s--) {
    for (int cnt_s = s; cnt_s > 1; cnt_s--) {
      printf(" ");
    }

    int cnt_q = 1;

    for ( ; cnt_q <= cnt; cnt_q++) {
      if (cnt_q == cnt) {
        printf("*\n");
      }else {
        printf("*");
      }
    }

    cnt += 2;
  }

  int CNT_S = 1;
  int mask = 0;
  int tag = 1;

  for (int S = n - 2; S > 0; S--) {
    int cnt_S = 1;
    for (int cnt_S = 1 ; cnt_S <= CNT_S; cnt_S++) {
      mask++;
      if (cnt_S == 1 && tag == 0) {
        printf("\n ");
      }else {
        printf(" ");
      }
    }

    int cnt_Q = 2 * (n - 1) - 3;

    for ( ; cnt_Q > 0; cnt_Q--) {
      if (cnt_Q == 1) {
        printf("*");
      }else {
        printf("*");
      }
    }

    CNT += 1;
    n--;
    CNT_S++;
    tag = 0;
  }

  return 0;
}

计算某分数序列的前n项之和

#include <stdio.h>

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

  double sum = 0.0;
    int cnt = 0;
  double i = 2.0;
  double j = 1.0;
  double k = 2.0;

  for (cnt = 0; cnt < n; cnt++) {
    sum += i / j;
    k = i;
    i += j;
    j = k;
  }

  printf("%lf", sum);

  return 0;
}

素数

#include <stdio.h>

int main()
{
  int num;
  int i;
  int isprime = 1;

  scanf("%d", &num);

  if (num == 1) {
    printf("NO");
    goto final;
  }else {

  for (i = 2; i < num; i++){
    if (num % i == 0){
      isprime = 0;
      break;
    }

  }
  if (isprime == 1) {
    printf("YES");
  }else {
      printf("NO");
  }
}
final:

  return 0;
}

第五章2

寻找250

#include <stdio.h>

int main ()
{
    int result = 1;
    int cnt = 0;

  do {
    int num = 0;
    result = scanf("%d", &num);
    cnt++;
    if (num == 250) {
      break;
    }
  }while (result == 1);

  printf("%d", cnt);

  return 0;

}

计算阶乘和

#include <stdio.h>

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

  int cnt = 1;
  int s = 0;

  do {
    int count = 1;
    int cur = 1;
    while (count <= cnt) {
      cur = count * cur;
      count++;
      }
    s += cur;
    cnt++;
  } while (cnt <= n);

  printf("%d", s);

  return 0;
}

整除光棍

#include<stdio.h>

int main()
{
  int x;
  scanf("%d", &x);
  int count = 1;
  int a = 1;

  while (a < x) {
    a = a * 10 + 1;
    count++;
  }
  printf("%d", a / x);

  int t = a % x;

  while (t != 0) {      //利用循环将商从高到低位依次输出，直到余数为0。
    t = t * 10 + 1;
    printf("%d", t / x);
    count++;
    t %= x;
  }
  printf(" %d", count);

  return 0;
}

求幂级数展开的部分和

#include <stdio.h>

int main ()
{
  double x;
  scanf("%lf", &x);

  double res = 1;
  int t = x;
  double temp = 1;
  int cnt = 1;

  while (temp >= 0.000001) {
    temp = temp * x / cnt;
    res += temp;
    cnt++;
  }

  printf("%.5f", res);

  return 0;
}

求奇数和

#include <stdio.h>

int main ()
{
  int num = 1;
  int temp = 0;
  int res = 0;

  while (num > 0) {
    scanf("%d", &num);
    if (num > 0) {
      temp = num % 2;
      if (temp != 0) {
        res += num;
        }
    }

  }

  printf("%d", res);

  return 0;
}

猴子吃桃问题

#include <stdio.h>

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

  int res = 1;

  for (int cnt = 1; cnt < n; cnt++) {
    res = (res + 1) * 2;
  }

  printf("%d", res);

  return 0;
}

水仙花数

#include <stdio.h>

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

  int first = 1;
  int i = 1;

  while (i < n) {
    first *= 10;
    i++;
  }

    i = first;

    while (i < first * 10) {
      int t = i;
      int sum = 0;

      do {
        int d = t % 10;
        t /= 10;
        int p = d;
        int j = 1;

        while (j < n) {
          p *= d;
          j++;
      }
      sum += p;

    } while (t > 0);

    if (sum == i) {
      printf("%d\n", i);
    }

      i++;
  }

  return 0;
}

兔子繁衍问题

#include <stdio.h>

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

    if (N <= 1) {
        printf("1\n");
        return 0;
    }

    int a = 1;
    int b = 1;
    int month = 2;

    while (b < N) {
        int c = a + b;
        a = b;
        b = c;
        month++;
    }

    printf("%d\n", month);
    return 0;
}

黑洞数

#include <stdio.h>

int main ()
{
  int num = 0;
  scanf("%d", &num);

  int x = num;
  int temp = 0;
  int X = 0;
  int cnt = 1;

  do {
    int c = 0;
    int b = 0;
    int a = 0;

    c = x / 100;
    b = x / 10 - c * 10;
    a = x - c * 100 - b * 10;

    if (a > b) {
      if (b > c) {
        temp = a * 100 + b * 10 + c;
        x = c * 100 + b * 10 + a;
      }else if (a > c) {
        temp = a * 100 + c * 10 + b;
        x = b * 100 + c * 10 + a;
      }else {
        temp = c * 100 + a * 10 + b;
        x = b * 100 + a * 10 + c;
      }
    }else if (a > c) {
      temp = b * 100 + a * 10 + c;
      x = c * 100 + a * 10 + b;
    }else if (b > c) {
      temp = b * 100 + c * 10 + a;
      x = a * 100 + c * 10 + b;
    }else {
      temp = c * 100 + b * 10 + a;
      x = a * 100 + b * 10 + c;
    }

      int mask = temp - x;
      if (mask == 495) {
        printf("%d: %d - %d = %d", cnt, temp, x, mask);
    }else {
          printf("%d: %d - %d = %d\n", cnt, temp, x, mask);
     }
    X = x;
    x = mask;
    cnt++;

  }while (temp - X != 495);

  return 0;
}

输出三角形字符阵列

#include <stdio.h>

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

  char chr = 'A';
  int cnt = 0;
  int N = n;
  int mask = 1;

  while (cnt <= n) {

    if (N == 1 && mask == 1) {
      printf("%c\n", chr);
    }else if (N > 1 && mask == 1) {
      printf("%c ", chr);
    }else if (N == 1 && mask == 0) {
      printf("%c", chr);
    }

    chr++;
    N--;

    if (N == 0) {
      n -= 1;
      N = n;
      cnt = 0;
    }

    if (N == 1 && n == 1) {
      mask = 0;
    }

    cnt++;

  }

  return 0;

}

求整数的位数及各位数字之和

#include <stdio.h>

int main() {
    long long N;
    scanf("%lld", &N);

    int digits = 0;
    int sum = 0;
    long long temp = N;

    while (temp > 0) {
        sum += temp % 10;
        temp /= 10;
        digits++;
    }

    printf("%d %d\n", digits, sum);
    return 0;
}

特殊a串数列求和

#include <stdio.h>

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

  int temp = a;
  int res = a;

  for (int cnt = 0; cnt < n - 1; cnt++) {
    temp = temp * 10 + a;
    res += temp;

  }

  printf("%d", res);

  return 0;
}

验证“哥德巴赫猜想”

#include <stdio.h>

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

  long int b = 0;
  long int num1 = 0;
  long int num2 = 0;

  for (long int t = 2; t <= n; t++) {
    int isPrime = 1;

    for (long int i = 2; i * i < t; i++) {
      if (t % i == 0 && t != 2) {
        isPrime = 0;
        break;
      }
    }

    if (isPrime == 1) {
      num1 = t;
      b = n - t;
    }

    int isprime = 1;

    for (long int j = 2; j * j < b; j++) {
      if (b % j == 0 && b != 2) {
        isprime = 0;
        break;
      }
    }

    if (isprime == 1) {
      num2 = b;
      break;
    }
  }

  printf("%ld = %ld + %ld", n, num1, num2);

  return 0;

}

换硬币

#include <stdio.h>

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

  int one;
  int two;
  int five;
  int mask = 0;

  for (five = x / 5; five != 0; five--) {
    for (two = x / 2; two != 0; two--) {
      for (one = x - 1; one != 0; one--) {
        if (one + two * 2 + five * 5 == x) {
          int cnt = one + two + five;
          printf("fen5:%d, fen2:%d, fen1:%d, total:%d\n", five, two, one, cnt);
          mask++;
        }
      }
    }
  }

  printf("count = %d", mask);

  return 0;
}

统计素数并求和

#include <stdio.h>

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

  int cnt = 0;
  int res = 0;

  if (m < 2) {
    m = 2;
  }

  for (int t = m; t <= n; t++) {
    int isPrime = 1;
    for (int x = 2; x < t; x++) {
      int rem = t % x;
      if (rem == 0) {
        isPrime = 0;
        break;
      }
    }
    if (isPrime == 1) {
      res += t;
      cnt++;
    }
  }

  printf("%d %d", cnt, res);

  return 0;
}

求e的近似值

#include <stdio.h>

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

  double e = 1;
  double res = 1;

  for (int num = 1; num <= n; num++) {
    res = 1;
    for (int t = 1; t <= num; t++) {
      res *= t;
    }
    e += 1.0 / res;
  }

  printf("%.8f", e);

  return 0;
}

求平方与倒数序列的部分和

#include <stdio.h>

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

  double s = 0;

  for ( ; m <= n; m++) {
    s += m * m + 1.0 / m;
  }

  printf("%.6f", s);

  return 0;
}

求组合数

#include <stdio.h>

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

  double N = 1;

  for (int numN = 1; numN <= n; numN++) {
    N *= numN;
  }

  double M = 1;

  for (int numM = 1; numM <= m; numM++) {
    M *= numM;
  }

  double C = 1;

  for (int numC = 1; numC <= m - n; numC++) {
    C *= numC;
  }

  double res = M / N / C;

  printf("%.0f", res);

  return 0;
}

求简单交错序列前N项和

#include <stdio.h>

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

  int den = 1;
  double s = 0;
  int sign = 1;

  for (int cnt = 0; cnt < n; cnt++) {
    s += sign * 1.0 / den;
    den += 3;
    sign = -sign;
  }

  printf("%.4f", s);

  return 0;
}

最佳情侣身高差

#include <stdio.h>

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

    char x;
  double h;
  int cnt = 0;

  do {
      scanf(" %c", &x);
    scanf("%lf", &h);
    if (x == 'M') {
      h /= 1.09;
    }else {
      h *= 1.09;
    }

    printf("%.2f\n", h);
    cnt++;
    } while (cnt < n);

    return 0;
}