写一个函数，模拟strstr()函数

#include<iostream>using namespace std;const char*strst1(const char* string, const char* strCharSet){for (int i = 0; string[i] != '\0'; i++){  //依次进行大串遍历int temp;temp = i;  //做标记和传递作用int j = 0;while (string[i++] == strCharSet[j++]){if (strCharSet[j] == '\0'){return &string[temp]; //遍历比较完成，则返回起始位置到串尾的组成的串}}i = temp;}return NULL;}int main(){char*string = "12345678";char strCharSet[10] = {};cin >> strCharSet;   //输入如果大于等于10则，内存错误const char *p = strst1(string, strCharSet);if (p != NULL){cout << p << endl;}elsecout << "no exist!" << endl;getchar();getchar();return 0;}