Rubayat Assignment

RubayatAssignment.cpp

#include <iostream>
#include <vector>
#include <algorithm>
#include <ctime>

void bubbleSort(std::vector<int>& arr) {
    int n = arr.size();
    for (int i = 0; i < n - 1; ++i) {
        for (int j = 0; j < n - i - 1; ++j) {
            if (arr[j] > arr[j + 1]) {
                std::swap(arr[j], arr[j + 1]);
            }
        }
    }
}

void merge(std::vector<int>& arr, int left, int mid, int right) {
    int n1 = mid - left + 1;
    int n2 = right - mid;

    std::vector<int> L(n1), R(n2);

    for (int i = 0; i < n1; ++i) {
        L[i] = arr[left + i];
    }
    for (int j = 0; j < n2; ++j) {
        R[j] = arr[mid + 1 + j];
    }

    int i = 0, j = 0, k = left;

    while (i < n1 && j < n2) {
        if (L[i] <= R[j]) {
            arr[k] = L[i];
            ++i;
        }
        else {
            arr[k] = R[j];
            ++j;
        }
        ++k;
    }

    while (i < n1) {
        arr[k] = L[i];
        ++i;
        ++k;
    }

    while (j < n2) {
        arr[k] = R[j];
        ++j;
        ++k;
    }
}

void mergeSort(std::vector<int>& arr, int left, int right) {
    if (left < right) {
        int mid = left + (right - left) / 2;

        mergeSort(arr, left, mid);
        mergeSort(arr, mid + 1, right);

        merge(arr, left, mid, right);
    }
}


void heapify(std::vector<int>& arr, int n, int i) {
    int largest = i;
    int left = 2 * i + 1;
    int right = 2 * i + 2;

    if (left < n && arr[left] > arr[largest]) {
        largest = left;
    }

    if (right < n && arr[right] > arr[largest]) {
        largest = right;
    }

    if (largest != i) {
        std::swap(arr[i], arr[largest]);
        heapify(arr, n, largest);
    }
}

void heapSort(std::vector<int>& arr) {
    int n = arr.size();

    for (int i = n / 2 - 1; i >= 0; --i) {
        heapify(arr, n, i);
    }

    for (int i = n - 1; i >= 0; --i) {
        std::swap(arr[0], arr[i]);
        heapify(arr, i, 0);
    }
}

void selectionSort(std::vector<int>& arr) {
    int n = arr.size();

    for (int i = 0; i < n - 1; ++i) {
        int minIndex = i;
        for (int j = i + 1; j < n; ++j) {
            if (arr[j] < arr[minIndex]) {
                minIndex = j;
            }
        }
        std::swap(arr[i], arr[minIndex]);
    }
}

int partition(std::vector<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;
            std::swap(arr[i], arr[j]);
        }
    }

    std::swap(arr[i + 1], arr[high]);
    return i + 1;
}

void quickSort(std::vector<int>& arr, int low, int high) {
    if (low < high) {
        int pi = partition(arr, low, high);
        quickSort(arr, low, pi - 1);
        quickSort(arr, pi + 1, high);
    }
}

void printExecutionTime(const std::string& algorithm, clock_t start, clock_t end) {
    double duration = static_cast<double>(end - start) / CLOCKS_PER_SEC * 1000.0;
    std::cout << algorithm << ": " << duration << " ms" << std::endl;
}

int main() {
    // Create an array
    std::vector<int> arr = { 5, 2, 9, 1, 3 };
    // Quick Sort
    clock_t start = clock();
    quickSort(arr, 0, arr.size() - 1);
    clock_t end = clock();
    printExecutionTime("Quick Sort", start, end);
    // Selection Sort
     start = clock();
    selectionSort(arr);
     end = clock();
    printExecutionTime("Selection Sort", start, end);

        // Heap Sort
     start = clock();
    heapSort(arr);
     end = clock();
    printExecutionTime("Heap Sort", start, end);

    // Bubble Sort
     start = clock();
    bubbleSort(arr);
     end = clock();
    printExecutionTime("Bubble Sort", start, end);

     // Merge Sort
     start = clock();
    mergeSort(arr, 0, arr.size() - 1);
     end = clock();
    printExecutionTime("Merge Sort", start, end);

    return 0;
}