1155 Heap Paths (30分)

#include<iostream>
#include<vector>

using namespace std;

const int N = 1010;

int heap[N];
int n, flag;
int isMax, isMin;
vector<int> ans;

void dfs(int u){
    ans.push_back(heap[u]);
    int l = u * 2, r = u * 2 + 1;
    if(l > n){
        cout << ans[0];
        for(int i = 1; i < ans.size(); i ++){
            cout << ' ';
            if(ans[i] > ans[i - 1]) isMin = 1;
            if(ans[i] < ans[i - 1]) isMax = 1;
            cout << ans[i];
        }
        puts("");
        return;
    }
    
    if(r <= n){
        dfs(r);
        ans.pop_back();
    } 
    
    if(l <= n){
        dfs(l);
        ans.pop_back();
    }
    
}

int main(){
    cin >> n;
    
    for(int i = 1; i <= n; i ++) cin >> heap[i];
    
    dfs(1);
    
    if(isMax && isMin) puts("Not Heap");
    else if(isMax) puts("Max Heap");
    else puts("Min Heap");
    
    return 0;
}

第四个测试点到底是啥？？？？？
应该是判断的时候错了
wa代码

#include<iostream>
#include<vector>

using namespace std;

#define LL long long

const int N = 1010;

LL heap[N];
int n, flag;
LL k;
vector<LL> ans;

void dfs(int u){
    ans.push_back(heap[u]);
    int l = u * 2, r = u * 2 + 1;
    if(l > n){
        if(ans.size() > 1) k = ans[0] - ans[1];
        for(int i = 0; i < ans.size(); i ++){
            cout << ans[i] << (i == ans.size() - 1 ? "
" : " ");
            if(i >= 2 && (ans[i] - ans[i - 1]) * (ans[i - 1] - ans[i - 2]) < 0) flag = 1;
        }
        
        return;
    }
    
    if(r <= n){
        dfs(r);
        ans.pop_back();
    } 
    
    if(l <= n){
        dfs(l);
        ans.pop_back();
    }
    
}

int main(){
    cin >> n;
    
    for(int i = 1; i <= n; i ++) cin >> heap[i];
    
    dfs(1);
    
    if(flag) puts("Not Heap");
    else if(k > 0) puts("Max Heap");
    else puts("Min Heap");
    
    return 0;
}