PAT-1147（Heaps）最大堆和最小堆的判断+构建树

Heaps

PAT-1147

#include<iostream>
#include<cstring>
#include<string>
#include<algorithm>
#include<cstdio>
#include<sstream>
#include<set>
#include<map>
#include<cmath>
#include<vector> 
#include<unordered_map>
using namespace std;
int m,n;
const int maxn=1003;
int tree[maxn];
vector<int>ve;
void afterOrder(int num){
	if(num>n){
		return;
	}
	afterOrder(num<<1);
	afterOrder(num<<1|1);
	ve.push_back(tree[num]);
}
int main(){
	cin>>m>>n;
	while(m--){
		ve.clear();
		for(int i=1;i<=n;i++){
			cin>>tree[i];
		}
		int flag=0;
		for(int i=1;i<=n;i++){
			int lnode=i<<1;
			int rnode=i<<1|1;
			if(lnode>n)
				lnode=i;
			if(rnode>n)
				rnode=i;
			if(tree[i]>=tree[lnode]&&tree[i]>=tree[rnode]){
				if(tree[i]>tree[lnode]||tree[i]>tree[rnode]){
					if(flag==1){//原来是小根堆 
						flag=-1;
					}else{
						if(flag==0)
							flag=2;
					} 
				}
				
			}else if(tree[i]<=tree[lnode]&&tree[i]<=tree[rnode]){
				if(tree[i]<tree[lnode]||tree[i]<tree[rnode]){
					if(flag==2)
						flag=-1;
					else{
						if(flag==0)
							flag=1;
					}
				}
				
			}else{
				flag=-1;
			}
//			cout<<flag<<endl;
		}
		afterOrder(1);
		if(flag==-1){
			cout<<"Not Heap"<<endl;
		}else if(flag==1){
			cout<<"Min Heap"<<endl;
		}else{
			cout<<"Max Heap"<<endl;
		}
		for(int i=0;i<ve.size();i++){
			if(i==(int)ve.size()-1){
				cout<<ve[i]<<endl;
			}else cout<<ve[i]<<" ";
		}
	}
	return 0;
}

另一种更好的判断最大堆最小堆的方法：

#include<iostream>
#include<vector>
using namespace std;
const int maxn=1005;
int n,m;
vector<int> v(maxn);
void dfs(int i){
    if(i>m)return;
    dfs(2*i);
    dfs(2*i+1);
    printf("%d%s",v[i],i==1?"\n":" ");
}
int main(){
    cin>>n>>m;
    for(int i=0;i<n;i++){
        int minheap=1,maxheap=1;
        for(int j=1;j<=m;j++){
            scanf("%d",&v[j]);
            if(j>1 && v[j/2]>v[j])minheap=0;
            if(j>1 && v[j/2]<v[j])maxheap=0;
        }
        if(minheap==1)printf("Min Heap\n");
        else printf("%s\n",maxheap==1?"Max Heap":"Not Heap");
        dfs(1);
    }
    
    return 0;
}