编写一个函数利用指针在字符串s中的指定位置pos处这里插入的位置是从1开始不是下标插入字符串。插入的位置和内容是从键盘输入要求：子函数 char InsertStrchar sint poschar t

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

char *InsertStr(char *s, int pos, char *t) {
    int len1 = strlen(s);
    int len2 = strlen(t);
    if (pos < 1 || pos > len1 + 1) {
        printf("Invalid position!\n");
        return s;
    }
    char *new_s = (char *)malloc(sizeof(char) * (len1 + len2 + 1));
    strncpy(new_s, s, pos - 1);
    strncpy(new_s + pos - 1, t, len2);
    strncpy(new_s + pos - 1 + len2, s + pos - 1, len1 - pos + 1);
    new_s[len1 + len2] = '\0';
    return new_s;
}

int main() {
    char s[100], t[100];
    int pos;
    printf("Enter the original string: ");
    scanf("%s", s);
    printf("Enter the position to insert (starting from 1): ");
    scanf("%d", &pos);
    printf("Enter the string to insert: ");
    scanf("%s", t);
    char *new_s = InsertStr(s, pos, t);
    printf("The new string is: %s\n", new_s);
    free(new_s);
    return 0;
}
``