题解 SP1805 【HISTOGRA - Largest Rectangle in a Histogram】

地表最强男人 · 2019-05-09 17:34:39 · 题解

C++bug之STL

思路很清晰，上代码：

#include<iostream>
#include<cstring>
#include<cstdio>
#include<algorithm>
#include<string>
#include<stack>
using namespace std;
long long n;
long long ans,a[1000010],w[1000010];
stack<long long> s;
int main()
{
    cin>>n;
    while(n!=0)
    {
        memset(a,0,sizeof(a));
        memset(w,0,sizeof(w));
        ans=0;
        a[n+1]=0;
        for(int i=1;i<=n;i++)
            cin>>a[i];  
        for(int i=1;i<=n+1;i++)
        {
            if(s.empty()||a[i]>s.top())
                s.push(a[i]),w[s.size()]=1;
            else
            {
                long long wi=0;
                while(s.size()&&s.top()>a[i])
                {
                    wi+=w[s.size()];
                    ans=max(ans,(long long)wi*s.top());
                    s.pop();
                }
                s.push(a[i]),w[s.size()]=wi+1;
            }
        }
        cout<<ans<<endl;
        cin>>n;
    }   
    return 0;
}