习题2，

/* 调用pow求幂 */
#include<stdio.h>
#include<math.h>
int main(void)
{
    int i,n;
    double power;


    printf("Enter n:");
    scanf("%d",&n);
    for(i=0;i<=n;i++){
        power=pow(2,i);
        printf("pow(2,%d)=%.of\n",i,power);
    }



    return 0;
} 

#include<stdio.h>
int main(void)
{
    int num1,num2,a,b,c,d,e;


    a=num1+num2;
    b=num1-num2;
    c=num1*num2;
    d=num1/num2;
    e=num1%num2;


    printf("a=%d,b=%d,c=%d,d=%d,e=%d\n",a,b,c,d,e);


    return 0;
}

/* 计算x的n次方 */
#include<stdio.h>
int main(void)
{
    int i,x,n,y;


    printf("Enter x:");
    scanf("%d",&x);
    printf("Enter n:");
    scanf("%d",&n);
    for(i=1;i<=n;i++){
        y=x*x;
    }
    printf("输出y为%d",x,n,y);



    return 0;
}
问题：是否y的定义没定好，输出的y等于x?

/* 求i*i+1/i的循环 */
#include<stdio.h>
int main(void)
{
    int i,m,n,sum;


    printf("Enter n,m:");
    scanf("%d%d",&n,&m);
    sum=0;
    for(i=m;i<=n;i++){
        sum=sum+(i*i+1/i);
    }
    printf("Sum=&Lf\n",sum);

    return 0;
}

/* 求i*i+1/i的循环 */
#include<stdio.h>
int main(void)
{
    int i,m,n,sum;


    printf("Enter n,m:");
    scanf("%d%d",&n,&m);
    sum=0;
    for(i=m;i<=n;i++){
        sum=sum+(i*i+1/i);
    }
    printf("Sum=&Lf\n",sum);

    return 0;
}