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;
}