college/Spring-2024/CS-2124/Assignment-2/src/part_three.c

#include "lib/lib.h"
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

void swap(int *a, int *b) {
    int t = *a;
    *a = *b;
    *b = t;
}

int partition(int arr[], int low, int high) {
    int pivot = arr[high];
    int i = (low - 1);

    for (int j = low; j <= high - 1; j++) {
        if (arr[j] < pivot) {
            i++;
            swap(&arr[i], &arr[j]);
        }
    }
    swap(&arr[i + 1], &arr[high]);
    return (i + 1);
}

void q_sort(int arr[], int low, int high) {
    if (low < high) {
        int p = partition(arr, low, high);
        q_sort(arr, low, p - 1);
        q_sort(arr, p + 1, high);
    }
}

int bsearch_iterative(int arr[], int key, int len) {
    int low = 0;
    int high = len;
    while (low < high) {
        int mid = (low + high) / 2;
        if (key == arr[mid]) {
            return mid;
        } else if (key > arr[mid]) {
            low = mid + 1;
        } else {
            high = mid - 1;
        }
    }
    return -1;
}

int bsearch_recursive(int arr[], int key, int low, int high) {
    if (low > high) {
        return -1;
    }

    int mid = (low + high) / 2;
    if (key == arr[mid]) {
        return mid;
    } else if (key > arr[mid]) {
        return bsearch_recursive(arr, key, mid + 1, high);
    } else {
        return bsearch_recursive(arr, key, low, mid - 1);
    }
}

int main() {
    print_header();
    printf("Enter 5 elements:\n");
    int arr_len = 5;
    int arr[arr_len];
    for (int i = 0; i < arr_len; i++) {
        scanf("%d", &arr[i]);
    }
    printf("\nEnter element to search for:\n");
    int search_element;
    scanf("%d", &search_element);
    q_sort(arr, 0, arr_len);

    clock_t tic, toc;
    printf("\n\n--------\n=> Binary Search (Iterative Approach)\n");
    tic = clock();
    int b_iter_index = bsearch_iterative(arr, search_element, arr_len);
    toc = clock();
    if (b_iter_index == -1) {
        printf("Unable to find the element '%d'!\n", search_element);
    } else {
        printf("Element found at index '%d', position '%d'\n", b_iter_index, b_iter_index + 1);
    }
    printf("Total time taken by CPU (End Time - Start Time)/clock per sec: %f\n--------\n",
           (double)(toc - tic) / CLOCKS_PER_SEC);

    printf("\n--------\n=> Binary Search (Recursive Approach)\n");
    tic = clock();
    int b_rec_index = bsearch_recursive(arr, search_element, 0, arr_len);
    toc = clock();
    if (b_iter_index == -1) {
        printf("Unable to find the element '%d'!\n", search_element);
    } else {
        printf("Element found at index '%d', position '%d'\n", b_rec_index, b_rec_index + 1);
    }
    printf("Total time taken by CPU (End Time - Start Time)/clock per sec: %f\n--------\n",
           (double)(toc - tic) / CLOCKS_PER_SEC);

    return EXIT_SUCCESS;
}