代码

#include <algorithm>

void merge(int a[], int low, int high) {
	static int t[N];
	if (low < high) {
		int mid = low + (high - low) / 2;
		merge(a, low, mid);
		merge(a, mid + 1, high);
		int p = low, q = mid + 1, s = low;
		while (p <= mid && q <= high) {
			t[s++] = a[p] < a[q] ? a[p++] : a[q++];
		}
		while (p <= mid || q <= high) {
			t[s++] = p <= mid ? a[p++] : a[q++];
		}
		for (int i = low; i <= high; i++) a[i] = t[i];
	}
}
void sort(unsigned *a, int n) {
	merge(a, 0, n - 1);
}

评测结果