Write strstr

Lab C Advanced 30 points

Write int find(char *text, char *word) that returns the index of the first occurrence of word in text, or -1, using nested loops. Read a line and a word and print the index.

Input

Line 1: text. Line 2: word.

Output

An index.

Example

Input

the cat sat on the mat
sat

Output

Sample input available Sample output available

Editor

Hints

Try every starting position; compare character by character.

Solution explanation

This brute-force search is O(n·m); real libraries use smarter algorithms for long texts.

Show solution

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

int find(char *text, char *word) {
    int n = strlen(text), m = strlen(word);
    for (int i = 0; i + m <= n; i++) {
        int j = 0;
        while (j < m && text[i + j] == word[j]) j++;
        if (j == m) return i;
    }
    return -1;
}

int main() {
    char text[200], word[50];
    fgets(text, 200, stdin);
    text[strcspn(text, "\n")] = '\0';
    scanf("%s", word);
    printf("%d\n", find(text, word));
    return 0;
}

Output

Answer