Escriba un programa en C++ que implemente el algoritmo MergeSort. El programa debe ordenar un array de enteros en orden ascendente mediante la técnica de divide y vencerás. Implemente la función de fusión para combinar dos arrays ordenados en uno solo.
Implemente el algoritmo MergeSort.
#include <iostream> // Include the input-output stream library
#include <vector> // Include the vector library to use dynamic arrays
using namespace std;
// Function to merge two sorted subarrays into a single sorted array
void merge(vector<int> &arr, int left, int mid, int right) {
int n1 = mid - left + 1; // Size of the first subarray
int n2 = right - mid; // Size of the second subarray
// Create temporary arrays to hold the data
vector<int> L(n1), R(n2);
// Copy data to temporary arrays L[] and R[]
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; // Initial index of the first subarray
int j = 0; // Initial index of the second subarray
int k = left; // Initial index of the merged subarray
// Merge the temporary arrays back into arr[left..right]
while (i < n1 && j < n2) {
if (L[i] <= R[j]) {
arr[k] = L[i];
i++;
} else {
arr[k] = R[j];
j++;
}
k++;
}
// Copy any remaining elements of L[], if any
while (i < n1) {
arr[k] = L[i];
i++;
k++;
}
// Copy any remaining elements of R[], if any
while (j < n2) {
arr[k] = R[j];
j++;
k++;
}
}
// Function to implement MergeSort recursively
void mergeSort(vector<int> &arr, int left, int right) {
if (left < right) {
int mid = left + (right - left) / 2; // Find the midpoint
// Recursively sort the first and second halves
mergeSort(arr, left, mid);
mergeSort(arr, mid + 1, right);
// Merge the sorted halves
merge(arr, left, mid, right);
}
}
int main() {
// Define an array to be sorted
vector<int> arr = {38, 27, 43, 3, 9, 82, 10};
// Get the number of elements in the array
int size = arr.size();
// Call mergeSort to sort the array
mergeSort(arr, 0, size - 1);
// Display the sorted array
cout << "Sorted array: ";
for (int i = 0; i < size; i++) {
cout << arr[i] << " ";
}
cout << endl;
return 0;
}
Salida
Sorted array: 3 9 10 27 38 43 82