#include<stdio.h>int main(){    int i,sum=0;    sum=0;    for(i=1;i<=100;i++)    sum+=i;    printf("sum=%d\n",sum);    return 0;}

#include<stdio.h>int main(){    int n,i,jiec=1;    printf("请输入一个整数n:");    scanf("%d",&n);    i=n;    while(i>1){        jiec=jiec*i;        i--;    }    printf("%d!=%d\n",n,jiec);        return 0;}

#include<stdio.h>int main(){    int k,sum=0;    for(k=1;k<=100;k++)        sum+=k;    printf("sum=%d\n",sum);        for(k=1;k<=50;k++)        sum=sum+k*k;    printf("sum=%d\n",sum);        for(k=1;k<=10;k++)        sum=sum+1.0/k;    printf("sum=%d\n",sum);    return 0;}

#include<stdio.h>int main(){    char c;    int zm=0,sz=0,kg=0,qt=0;    while((c=getchar())!=‘\n‘){        if(c>=‘a‘&&c<=‘z‘||c>=‘A‘&&c<=‘Z‘)            zm++;        else if(c==‘ ‘)            kg++;        else if(c>=‘0‘&&c<=‘9‘)            sz++;        else        qt++;    }    printf("字母个数；%d\n",zm);    printf("空格个数；%d\n",kg);    printf("数字个数；%d\n",sz);    printf("其他个数；%d\n",qt);    return 0;}

#include<stdio.h>int main(){    int m,n,t,i,gys=1,gbs;    printf("请输入两个整数；");    scanf("%d%d",&m,&n);    if(n>m){        t=m;        m=n;        n=t;        }    for(i=n;i>=1;i--)        if(m%i==0&&n%i==0)            break;        printf("m=%d，n=%d",m,n);    if(i!=0){        gys=i;        printf("，最大公约数为；%d\n",gys);    }        gbs=m*n/gys;        printf("最大公倍数为；%d\n",gbs);    return 0;}