归并排序代码

#define MAX 自定义
int a[MAX],b[MAX];
//归并排序从小到大
void digui(int i, int j) {
	if (i >= j) {
		return;
	}
	int mid = i + (j - i) / 2;
	digui(i, mid);
	digui(mid + 1, j);
	int r = i, l = mid + 1, h = i;
	while (r <= mid && l <= j) {
		if (a[r].x < a[l].x) {
			e[h].x = a[r].x;
			e[h].y = a[r].y;
			h++;
			r++;
		}
		else {
			e[h].x = a[l].x;
			e[h].y = a[l].y;
			h++;
			l++;
		}
	}
	while (r <= mid) {
		e[h].x = a[r].x;
		e[h].y = a[r].y;
		h++;
		r++;
	}
	while (l <= j) {
		e[h].x = a[l].x;
		e[h].y = a[l].y;
		h++;
		l++;
	}
	h = i;
	while (h <= j) {
		a[h].x = e[h].x;
		a[h].y = e[h].y;
		h++;
	}
}