比较两个数组（由字符串或字符组成）并且不打印它们的差异数

Question

为什么表示两个数组之间差异的差异输出为零？ 语言：C

#include <stdio.h>
#include <stdlib.h>
long int n=100000;
long int Difference=0;
long int q;
char *str1,*str2;
int main()
{
char string1[n];
char string2[n];
scanf("%ld",&q);
scanf("%s",&string1[q]);
scanf("%s",&string2[q]);
str1=string1;
str2=string2;
for(int i=0; str1[i]!='\0' && str2[i]!='\0'; i++)
{
if(str1[i]!=str2[i])
Difference+=1;
}
printf("%ld",Difference);
return 0;
}

Answer 1

假设变量 q 被用作内存偏移量，您需要将 char 指针 str1 和 str2 设置为数组中 scanf 存储从 stdin 读取的值的内存位置。

#include <stdio.h>
#include <stdlib.h>

long int n = 100000;
long int Difference = 0;
long int q;
char *str1,*str2;

int main()
{
    char string1[n];
    char string2[n];

    scanf("%ld",&q);
    scanf("%s",&string1[q]);
    scanf("%s",&string2[q]);

    // Set the char pointers to the address in the array
    // q distance from the initial address of the array 
    // because you stored your input strings at that address
    // and not at the beginning of the array in memory
    str1 = string1 + q;
    str2 = string2 + q;

    for(int i=0; str1[i] != '\0' && str2[i] != '\0'; i++)
    {
        if(str1[i] != str2[i])
            Difference += 1;
    }

    printf("%ld", Difference);
    return 0;
}