P2947 [USACO09MAR]向右看齐Look Up

标签：highlight   main   mat   pre   bsp   line   system   with   cow   

题目描述

Farmer John‘s N (1 <= N <= 100,000) cows, conveniently numbered 1..N, are once again standing in a row. Cow i has height H_i (1 <= H_i <= 1,000,000).

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

Note: about 50% of the test data will have N <= 1,000.

约翰的N(1≤N≤10^5)头奶牛站成一排，奶牛i的身高是Hi(l≤Hi≤1,000,000)．现在，每只奶牛都在向右看齐．对于奶牛i，如果奶牛j满足i<j且Hi<Hj，我们可以说奶牛i可以仰望奶牛j． 求出每只奶牛离她最近的仰望对象．

Input

输入输出格式

输入格式：

* Line 1: A single integer: N

* Lines 2..N+1: Line i+1 contains the single integer: H_i

第 1 行输入 N，之后每行输入一个身高 H_i。

输出格式：

* Lines 1..N: Line i contains a single integer representing the smallest index of a cow up to which cow i looks. If no such cow exists, print 0.

共 N 行，按顺序每行输出一只奶牛的最近仰望对象，如果没有仰望对象，输出 0。

输入输出样例

6 
3 
2 
6 
1 
1 
2 

3 
3 
0 
6 
6 
0 

说明

FJ has six cows of heights 3, 2, 6, 1, 1, and 2.

Cows 1 and 2 both look up to cow 3; cows 4 and 5 both look up to cow 6; and cows 3 and 6 do not look up to any cow.

【输入说明】6 头奶牛的身高分别为 3, 2, 6, 1, 1, 2.

【输出说明】奶牛#1,#2 仰望奶牛#3，奶牛#4,#5 仰望奶牛#6，奶牛#3 和#6 没有仰望对象。

【数据规模】

对于 20%的数据： 1≤N≤10；

对于 50%的数据： 1≤N≤1,000；

对于 100%的数据：1≤N≤100,000；1≤H_i≤1,000,000；

#include <cmath>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <iostream>
#include <algorithm>
using namespace std;
int s[100001],a[100001],n;
int main(){
    scanf("%d",&n);
    for(int IAKNOIP=1;IAKNOIP<=n;IAKNOIP++){
        scanf("%d",&a[IAKNOIP]);
    }
    for(int j,i=n-1;i>=1;i--){
        j=i+1;
        while((a[i]>=a[j])&&(a[j]>0)){
              j=s[j];
        }
        s[i]=j;
    }
    for(int IAKNOIP2018=1;IAKNOIP2018<=n;IAKNOIP2018++){
        printf("%d\n",s[IAKNOIP2018]);
    }
    ///*system("pause");*/
    return 0;
}

P2947 [USACO09MAR]向右看齐Look Up

标签：highlight   main   mat   pre   bsp   line   system   with   cow   

原文地址：https://www.cnblogs.com/xiongchongwen/p/11192366.html