cossak23/Java_rep

implementation of the merge sort algorithm for an integer array

public class MergeSort { public static void main(String[] args) { int[] arr = { 38, 27, 43, 3, 9, 82, 10 }; mergeSort(arr, 0, arr.length - 1); System.out.println("Sorted array: " + Arrays.toString(arr)); }

private static void mergeSort(int[] arr, int l, int r) {
    if (l < r) {
        int m = (l + r) / 2;
        mergeSort(arr, l, m);
        mergeSort(arr, m + 1, r);
        merge(arr, l, m, r);
    }
}

private static void merge(int[] arr, int l, int m, int r) {
    int n1 = m - l + 1;
    int n2 = r - m;
    int[] left = new int[n1];
    int[] right = new int[n2];

    for (int i = 0; i < n1; i++) {
        left[i] = arr[l + i];
    }
    for (int j = 0; j < n2; j++) {
        right[j] = arr[m + 1 + j];
    }

    int i = 0, j = 0;
    int k = l;
    while (i < n1 && j < n2) {
        if (left[i] <= right[j]) {
            arr[k] = left[i];
            i++;
        } else {
            arr[k] = right[j];
            j++;
        }
        k++;
    }

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

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

}