mergeSort

#include <stdio.h>
#define MAX_LEN 3000

int a[MAX_LEN], b[MAX_LEN];

void mergeSort(int l, int r)
{
    if (l == r)
        return;

    int m = (l + r) / 2;
    mergeSort(l, m);
    mergeSort(m + 1, r);

    int i = l, j = m + 1, k = l;
    while (i <= m || j <= r)
        if (i > m || (j <= r && a[i] > a[j]))
            b[k++] = a[j++];
        else
            b[k++] = a[i++];
    for (i = l; i <= r; i++)
        a[i] = b[i];
}

int main(int argc, char const *argv[])
{
    int i, n;
    printf("Number of elements: ");
    scanf("%d", &n);
    for (i = 0; i < n; i++)
        scanf("%d", &a[i]);
    mergeSort(0, n - 1);
    for (i = 0; i < n; i++)
        printf("%d ", a[i]);
    printf("\n");
    return 0;
}