【POJ】2559 Largest Rectangle in a Histogram

#include<cstdio>
#include<algorithm>
typedef __int64 LL;
#define MAXN 100010
using namespace std;
struct node
{
    LL w,h;
};
node st[MAXN];
int main()
{
    LL ans,wide;
    node temp;
    int n,i,top;
    while(scanf("%d",&n),n)
    {
        for(top=-1,ans=i=0;i<n;i++)
        {
            scanf("%I64d",&temp.h);
            for(wide=0;top>-1&&st[top].h>=temp.h;top--)
            {
                wide+=st[top].w;
                ans=max(ans,wide*st[top].h);
            }
            temp.w=wide+1;
            st[++top]=temp;
        }
        for(wide=0;top>-1;top--)
        {
            wide+=st[top].w;
            ans=max(ans,st[top].h*wide);
        }
        printf("%I64d\n",ans);
    }
    return 0;
}