王道C语言督学营OJ课后习题（课时4）_王道c语言课时4作业

#include <stdio.h>
 
int main() {
      int count=0;
    for (int i = 1; i <=10; ++i)
    {
        for (int n = 1; n <=20 ; ++n)
        {
 
                for (int i1 = 1; i1 <=40 ; ++i1)
                {
                    for (int j1 = 1; j1 <=40 ; ++j1)
                    {
                           if(i+n+i1+j1==40 && i*10+n*5+i1*2+j1==100 )
                               count++;
                    }
                }
 
        }
    }
    printf("%d\n",count);
    return 0;
    }
 
 

#include <stdio.h>
 
int main() {
    int i,a,c,sum=0;
    scanf("%d",&i);
    a=i;
    while (i)
    {
        c=i%10;
        sum=sum*10+c;
        i=i/10;
    }
    if(sum==a)
    {
        printf("yes");
    }
    else
    {
        printf("no");
    }
 
    return 0;
}

#include <stdio.h>
 
int main() {
    int n,sum=1;
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
        sum=sum*i;
    }
    printf("%d\n",sum);
    return 0;
}