排序3 Insertion or Heap Sort

题目：https://pintia.cn/problem-sets/1268384564738605056/problems/1289169858763866114
题解：https://www.liuchuo.net/archives/2273
代码：

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
void downAdjust(vector<int> &b, int low, int high) {
    int i = 1, j = i * 2;
    while(j <= high) {
        if(j + 1 <= high && b[j] < b[j + 1]) j = j + 1;
        if (b[i] >= b[j]) break;
        swap(b[i], b[j]);
        i = j; j = i * 2;
    }
}
int main() {
    int n, p = 2;
    scanf("%d", &n);
    vector<int> a(n + 1), b(n + 1);
    for(int i = 1; i <= n; i++) scanf("%d", &a[i]);
    for(int i = 1; i <= n; i++) scanf("%d", &b[i]);
    while(p <= n && b[p - 1] <= b[p]) p++;
    int index = p;
    while(p <= n && a[p] == b[p]) p++;
    if(p == n + 1) {
        printf("Insertion Sort\n");
        sort(b.begin() + 1, b.begin() + index + 1);
    } else {
        printf("Heap Sort\n");
        p = n;
        while(p > 2 && b[p] >= b[1]) p--;
        swap(b[1], b[p]);
        downAdjust(b, 1, p - 1);
    }
    printf("%d", b[1]);
    for(int i = 2; i <= n; i++)
        printf(" %d", b[i]);
    return 0;
}