栈的单调性 POJ 3250

经典的题目

#include <stdio.h>
#include <stack>
using namespace std;
int data[80000];
int N;
long long sum;
stack<int> s;
void getMax()
{
        s.push(data[0]);
        for(int i = 1; i <= N-1; i++)
        {
                // how many data can see data[i] (greater than data[i])?
                // they are all in the stack!
                while(!s.empty() && s.top() <= data[i])
                {
                        s.pop();
                }
                sum += (long long)s.size();
                s.push(data[i]);
        }
        printf("%lld/n", sum);
}
int main()
{
        scanf("%d", &N);
        for(int i = 0; i < N; i++)
        {
                scanf("%d", &data[i]);
        }
        getMax();
}