在C中查找字符串中子字符串的位置

char *strstr(const char *haystack, const char *needle);

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

int main() {
    char haystack[] = "This is a sample string.";
    char needle[] = "sample";
    char *result;

    result = strstr(haystack, needle);
    if (result != NULL) {
        printf("Substring found at position %ld\n", result - haystack);
    } else {
        printf("Substring not found\n");
    }

    return 0;
}