洛谷 P2947 [USACO09MAR]向右看齐Look Up

目录

• [TOC]
  • 题目
  • 思路
  • $Code$

题目

戳

思路

单调栈裸题

\(Code\)

#include<stack>
#include<cstdio>
#include<string>
#include<cstring>
#include<iostream>
#define MAXN 100001
#define rr register
using namespace std;
int n,ans[MAXN];
struct mu{
	int num,h;
}mumumu[MAXN];
stack<mu> sss;
inline int read(){
	int x=0;bool f=0;char c=getchar();
	while(c<'0'||c>'9'){if(c=='-')f=!f;c=getchar();}
	while(c>='0'&&c<='9'){x=x*10+c-'0';c=getchar();}
	return f?-x:x;
}
int main(){
	n=read();
	for(rr int i=1;i<=n;++i){
		mumumu[i].num=i;
		mumumu[i].h=read();
	}
	for(rr int i=n;i>=1;--i){
		if(i==n){
			sss.push(mumumu[n]);
			ans[i]=0;
		}else{
			while(mumumu[i].h>=sss.top().h){
				sss.pop();
				if(sss.empty()) break;
			}
			if(sss.empty()) ans[i]=0;
			else ans[i]=sss.top().num;
			sss.push(mumumu[i]);
		}
	}
	for(rr int i=1;i<=n;++i){
		printf("%d\n",ans[i]);
	}
	return 0;
}