51nod_1102_面积最大的矩形

#include<algorithm>
#include<cstdlib>
#include<iostream>
#include<cstring>
#include<cstdlib>
#include<queue>
#include<functional>
#include<utility>//pair
#define INF 0x7f7f7f7f
#define getrand(a,b) (int)((rand()/33000.0)*((b)-(a)+1))+(a)
using namespace std;
typedef long long LL;
const int maxnn=100+5;
const int maxn=100000+5;
const int mod=1e9+7;
priority_queue< pair<LL,int> > q;
int main()
{
    int n,x,m;
    LL ans=0;
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>x;
        m=1<<30;  //左侧  
        while((!q.empty())&&q.top().first>x){
            if(m>q.top().second) m=q.top().second;
            ans=max(ans,q.top().first*(i-q.top().second));
            q.pop();
        }
        if(m!=1<<30) q.push((pair<LL,int>){x,m});
        else q.push((pair<LL,int>){x,i});
    }
    while(!q.empty()){
        ans=max(ans,q.top().first*(n-q.top().second));
        q.pop();
    }
    cout<<ans<<endl;
    return 0;
}