#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
 
void swap_string_ptr(char **s1, char **s2){ 
    /* s1 と s2 のアドレスを交換する */
    char *tmp;
    tmp = *s1;
    *s1 = *s2;
    *s2 = tmp;
}
 
int main(void){
    char *str1 = "ABC";
    char *str2 = "123";
 
    /* str1 と str2 の値（文字列の先頭アドレス）を交換 */
    swap_string_ptr(&str1, &str2);
 
    printf("str1=%s, str2=%s\n", str1, str2);
 
    return 0;
}

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