c++归并排序

#include <iostream>

using namespace std;

const int N = 1e06 + 10;
int q[N], temp[N];
void merge_sort(int q[], int l, int r) {
    if (l >= r) return ;
    int mid = l + r >> 1;
    merge_sort(q, l, mid);
    merge_sort(q, mid + 1, r);
    int k = 0, i = l, j = mid + 1;
    while (i <= mid && j <= r) {
        if (q[i] <= q[j]) temp[k ++] = q[i++];
        else temp[k++] = q[j++];
        
    }
    while (i <= mid) temp[k++] = q[i++];
    while (j <= r) temp[k++] = q[j++];
    for (i = l, j = 0; i <= r; i++, j++) {
        q[i] = temp[j];
    }
}
int main() {
    int n, i;
    scanf("%d", &n);
    for (i = 0; i < n; i++) {
        scanf("%d", &q[i]);
    }
    merge_sort(q, 0, n - 1);
    for (i = 0; i < n; i++) {
        printf("%d ", q[i]);
    }
    return 0;
}

归并排序模板