程序执行只出现烫字。

#include
#define S 20
int main(void)
{
char arr1[S],arr2[S];
printf("请输入信息：");
scanf_s("%s", &arr1,S);
int n ,k;
k = 1 , n = 0;

while( k <= 100)
{
    while (n < 20)
    {
        if (arr1[n] + k > 126)
            arr2[n] = arr1[n] + k + 32 - 127;
        else
            arr2[n] = arr1[n] + k;

        n = n++;
    }
        printf("k=%d\n", k);
        printf("%s\n", &arr2[S]);
        k = k++;

}

return 0;

}

数组名就是地址，接收输入不需要 &

scanf_s("%s", arr1,S);

后面的printf也是

 printf("%s\n", arr2);