#include <stdio.h>
int find(char *string, char *substring) {
int i, j;
for (i = 0; string[i] != '\0'; i++) {
for (j = 0; substring[j] != '\0' && string[i + j] == substring[j]; j++);
if (substring[j] == '\0') {
return i; // substring found at index i
}
}
return -1; // substring not found
}
int main() {
char string[] = "Hello, World!";
char substring[] = "World";
int index = find(string, substring);
if (index != -1) {
printf("Substring found at index: %d\n", index);
} else {
printf("Substring not found\n");
}
return 0;
}
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