是将字符串中的input改为shuru可是就是改不过来

#include<stdio.h>
#include<string.h>
void main()
{
    char s[30];
    char *str = "input";
    void replace(char s[30], char *str);
    clrscr();
    printf("input a string:\n");
    scanf("%s", s);
    replace(s, str);
}
void replace(char s[30], char *str)
{
    int i, j;
    if (strstr(s, str)!=NULL)
    {
        i = strstr(s, str);
        s[i] = 's';s[i + 1] = 'h';
        s[i + 2] = 'u';s[i + 3] = 'r';
        s[i + 4] = 'u';
        printf("%s", s);
    }
    else printf("no found");
}
----------------解决方案--------------------------------------------------------
#include<stdio.h>
#include<string.h>
void main()
{
    char s[30];
    char *str = "input";
    void replace(char s[30], char *str);
    printf("input a string:\n");
    scanf("%s", s);
    replace(s, str);
}
void replace(char s[30], char *str)
{
    char * i;
    if (strstr(s, str)!=NULL)
    {
        i = strstr(s, str);
        *i= 's';*(++i) = 'h';
        *(++i) = 'u';*(++i) = 'r';
        *(++i) = 'u';
        printf("%s", s);
    }
    else printf("no found");
}
----------------解决方案--------------------------------------------------------