insertion_sort_&&_Radix_sort.cpp

// Ayush Bhardwaj
// Date : 12-02-23
#include <iostream>
using namespace std;

void insertionSort(int arr[], int n) {
    int i, key, j;
    for (i = 1; i < n; i++) {
        key = arr[i];
        j = i - 1;
        
        // Move elements of arr[0..i-1], that are greater than key, to one position ahead of their current position
        while (j >= 0 && arr[j] > key) {
            arr[j + 1] = arr[j];
            j = j - 1;
        }
        arr[j + 1] = key;
    }
}
void merge(int arr[], int l, int m, int r) {
    int i, j, k;
    int n1 = m - l + 1;
    int n2 = r - m;
    
    // Create temporary arrays
    int L[n1], R[n2];
    
    // Copy data to temporary arrays L[] and R[]
    for (i = 0; i < n1; i++) {
        L[i] = arr[l + i];
    }
    for (j = 0; j < n2; j++) {
        R[j] = arr[m + 1 + j];
    }
    i = 0; 
    j = 0; 
    k = l; 
    
    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(int arr[], int l, int r) {
    if (l < r) {
        int m = l + (r - l) / 2; // Same as (l+r)/2, but avoids overflow for large l and r
        mergeSort(arr, l, m);
        mergeSort(arr, m + 1, r);
        merge(arr, l, m, r);
    }
}

int main() {
    int n, i;
    cout << "Enter the number of elements: ";
    cin >> n;
    int arr[n];
    cout << "Enter " << n << " integers:";
    for(i = 0; i < n; i++) {
        cin >> arr[i];
    }
    // insertionSort(arr, n);
    mergeSort(arr, 0, n - 1);
    cout << "Sorted array:\n";
    for (i = 0; i < n; i++) {
        cout << arr[i] << " ";
    }
    cout << endl;
    return 0;
}