猴子向右看，FOJ上某题 单调栈

N (1 <= N <= 100,000) monkeys in the mountains, conveniently numbered 1..N, are once again standing in a row. Monkey i has height H_i (1 <= H_i <= 1,000,000).

Each monkey is looking to his left toward those with higher index numbers. We say that monkey i "looks up" to monkey j if i < j and H_i< H_j. For each monkey i, we would like to know the index of the first monkey in line looked up to
by monkey i.

Input

Input consists of several testcases. The format of each case as follow:

Output

For each testcase, output N lines. Line i contains a single integer representing the smallest index of a monkey up to which monkey i looks. If no such monkey exists, print 0.

Sample Input

6326112

Sample Output

330660

Hint

Monkey 1 and 2 both look up to monkey 3; monkey 4 and 5 both look up to monkey 6; and monkey 3 and 6 do not look up to any monkey.

题意：告诉n个一排猴子，每个猴子向右看，问第一个比自己高的猴子的位置，没有就输出0，最后一个也是0

#include <iostream>
#include <stdio.h>
#include <string>
#include <cstring>
#include <queue>
#include <cmath>
#include <algorithm>
#include <stack>
#define N 100009
using namespace std;

int a[N];

int main()
{
    int n;
    while(~scanf("%d",&n))
    {
        for(int i=1;i<=n;i++)
        {
            scanf("%d",&a[i]);
        }

        int ans[N];
        memset(ans,0,sizeof ans);
        ans[n]=n;//初始化为n，但是实际值为0
        for(int i=n-1;i>=1;i--)//找右边第一个比a[i]小的位置
        {
            int tt=i;
            while(tt<n&&a[i]>=a[tt+1]) tt=ans[tt+1];
            ans[i]=tt;
        }

        for(int i=1;i<n;i++)
        {
            if(ans[i]==n)//当是最后一个猴子的时候，并不一定保证比当前猴子高
            if(a[i]<a[n])
            printf("%d\n",ans[i]+1);
            else
            cout<<0<<endl;
            else
            printf("%d\n",ans[i]+1);

        }

        cout<<0<<endl;

    }
    return 0;
}

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