#include<stdio.h>
void main()
{
    int a, i;
    scanf("%d", &a);
    if (a%i == 0)
    {
        if (i < a) i = i + 1;
        printf("a=%d\n是素数");
    }
    else
        printf("a=%d\n不是素数");
        system("pause");
        return 0;
}

新手菜鸟，运行4，得出a=19700702不是素数。这是为什么呢？Run-Time Check Failure #3 - The variable 'i' is being used without being initialized.还有一个这个中断提醒。。。求解谢谢

#include<stdio.h>
void main()
{
    int a, i;
    i = 2;
    printf("\n请输入一个正整数");
    scanf("%d", &a);
    if (a < 1)
        printf("输入错误！\n");
    else
    {
        if (a%i == 0)
        {
            if (i < a) i = i + 1;
            printf("a=%d是素数\n",a);
        }
        else
            printf("a=%d不是素数\n,a");
    }
        system("pause");
        return 0;
}
这样呢，