c search in string code example

Example 1: check if string in string c

if(strstr(sent, word) != NULL) {
    /* ... */
}

Example 2: search a word in a string in c

/**
 * C program to find last occurrence of a word in given string
 */

#include <stdio.h>
#include <string.h>
#define MAX_SIZE 100 // Maximum string size

int main()
{
    char str[MAX_SIZE];
    char word[MAX_SIZE];
    int i, j, found;

    /* Input string and word from user */
    printf("Enter any string: ");
    gets(str);
    fflush(stdin);
    printf("Enter any word to search: ");
    gets(word);

    /*
     * Run a loop from starting index of string to
     * length of string - word length
     */
    for(i=0; i<strlen(str) - strlen(word); i++)
    {
        // Match word at current position
        found = 1;
        for(j=0; j<strlen(word); j++)
        {
            // If word is not matched
            if(str[i + j] != word[j])
            {
                found = 0;
                break;
            }
        }

        // If word have been found then print found message
        if(found == 1)
        {
            printf("'%s' found at index: %d \n", word, i);
        }
    }

    return 0;
}

Example 3: binary search in c

//C Implementation
#include<stdio.h>
int BinarySearch(int arr[], int search, int mid, int len){
    if(mid == -1 || mid == len+1){
        printf("\nSearched Element doesn't exist.");
        return 1;
    }
    else if (search > arr[mid]){
        mid++;
        BinarySearch(arr,search,mid,len);
        return 0;
    }
    else if (search < arr[mid]){
        mid--;
        BinarySearch(arr,search,mid,len);
        return 0;
    }
    else if(search == arr[mid]) {
        printf("\n Searched Element found at Location %d.",mid);
        return 1;
    } 
}
void main(){
    int arr[] = {1,2,3,4,5,6,7,8,9};
    int len = sizeof(arr) / sizeof(int);
    int mid = (int) (len / 2) + 1;
    printf("\n Please Enter Number You Want to Search \n >  ");
    int search;
    scanf("%d",&search);
    int Result = BinarySearch(arr,search,mid,len);
}