各位大神求帮忙！！！

. myAt函数，原型是int myAt(const char *s, char c, int n);功能是返回指定字符在指定字符串中第n次出现的位置（从0开始计算)

楼主请采纳，已解决！

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

int myAt(const char *s, char c, int n)
{
    int flag = 0;
    int index = 0;
    if (NULL == s)
    {
        return -1;
    }
    while (*s != '\0')
    {
        if (*s == c)
        {
            ++flag;
            ++index;
            ++s;
            if (flag == n)
            {
                return index;
            }
        }
        ++s;
        ++index;
    }
    return index;
}


int main()
{
    char *str = "welcome to you";
    int n =2;
    char ch = 'o';
    int index = 0;
    index = myAt(str,ch,n);
    printf("index = %d\n",index);
    system("pause");
    return 0;
}