#include <stdio.h>
#include <string.h>
// char *strstr(const char *haystack, const char *needle)
int indexOf(char* source, char* search) {
char* found = strstr(source, search);
if (found != NULL) {
return found - source;
}
return -1;
}
int main() {
char* source = "c c++ java python c#";
char* search = "java";
printf("%d\n", indexOf(source, search));
printf("%d\n", indexOf(source, "xy"));
return 0;
}
/*
run:
6
-1
*/