Codeforces Round #276 (Div. 1) E. Sign on Fence 二分+主席树
Bizon the Champion has recently finished painting his wood fence. The fence consists of a sequence of n panels of 1 meter width and of arbitrary height. The i-th panel's height is hi meters. The adjacent planks follow without a gap between them.
After Bizon painted the fence he decided to put a "for sale" sign on it. The sign will be drawn on a rectangular piece of paper and placed on the fence so that the sides of the sign are parallel to the fence panels and are also aligned with the edges of some panels. Bizon the Champion introduced the following constraints for the sign position:
- The width of the sign should be exactly w meters.
- The sign must fit into the segment of the fence from the l-th to the r-th panels, inclusive (also, it can't exceed the fence's bound in vertical direction).
The sign will be really pretty, So Bizon the Champion wants the sign's height to be as large as possible.
You are given the description of the fence and several queries for placing sign. For each query print the maximum possible height of the sign that can be placed on the corresponding segment of the fence with the given fixed width of the sign.
The first line of the input contains integer n — the number of panels in the fence (1 ≤ n ≤ 105).
The second line contains n space-separated integers hi, — the heights of the panels (1 ≤ hi ≤ 109).
The third line contains an integer m — the number of the queries (1 ≤ m ≤ 105).
The next m lines contain the descriptions of the queries, each query is represented by three integers l, r and w (1 ≤ l ≤ r ≤ n, 1 ≤ w ≤ r - l + 1) — the segment of the fence and the width of the sign respectively.
For each query print the answer on a separate line — the maximum height of the sign that can be put in the corresponding segment of the fence with all the conditions being satisfied.
5
1 2 2 3 3
3
2 5 3
2 5 2
1 5 5
2
3
1
The fence described in the sample looks as follows:

The possible positions for the signs for all queries are given below.
The optimal position of the sign for the first query.
The optimal position of the sign for the second query.
The optimal position of the sign for the third query.
题意:
给你n个数,每个数表示一个高度。
m个询问,每次询问你l,r内连续w个数的最低高度的最大值
note解释样例很详细
题解:
主席树的技巧
按照高度排序,倒着插入每一颗线段树中
查询的话,二分历史版本线段树的位置,在l,r这段区间内至少存在连续w个位置存在有值,很明显的线段树的区间合并,区间查询了
#include<bits/stdc++.h>
using namespace std;
#pragma comment(linker, "/STACK:102400000,102400000")
#define ls i<<1
#define rs ls | 1
#define mid ((ll+rr)>>1)
#define pii pair<int,int>
#define MP make_pair
typedef long long LL;
const long long INF = 1e18;
const double Pi = acos(-1.0);
const int N = 1e5+, M = 1e6, mod = 1e9+, inf = 2e9;
int n,root[N],m,l[N*],r[N*],rmx[N*],lmx[N*],mx[N*],sz,v[N*];
pair<int ,int > a[N];
void push_up(int i,int ll,int rr) {
lmx[i] = lmx[l[i]];
if(lmx[i] == mid - ll + ) lmx[i] += lmx[r[i]];
rmx[i] = rmx[r[i]];
if(rmx[i] == rr - mid) rmx[i] += rmx[l[i]];
mx[i] = max(lmx[r[i]]+rmx[l[i]],max(mx[l[i]],mx[r[i]]));
}
void update(int x,int &y,int ll,int rr,int k,int c) {
v[y = ++sz] = v[x] + ;
l[y] = l[x];
r[y] = r[x];
if(ll == rr) {
mx[y] = lmx[y] = rmx[y] = c;
l[y] = ; r[y] = ;
return ;
}
if(k <= mid) update(l[x],l[y],ll,mid,k,c);
else update(r[x],r[y],mid+,rr,k,c);
push_up(y,ll,rr);
}
int query(int i,int ll,int rr,int s,int t) {
if(s > t) return ;
if(s == ll && rr == t) return mx[i];
int ret = ;
if(t <= mid) ret = query(l[i],ll,mid,s,t);
else if(s > mid) ret = query(r[i],mid+,rr,s,t);
else {
ret = max(query(l[i],ll,mid,s,mid),query(r[i],mid+,rr,mid+,t));
int lx = min(rmx[l[i]],mid - s + );
int rx = min(lmx[r[i]],t - mid);
ret = max(ret, lx + rx);
}
return ret;
}
int main() {
scanf("%d",&n);
for(int i = ; i <= n; ++i) scanf("%d",&a[i].first),a[i].second = i;
sort(a+,a+n+);
for(int i = n; i >= ; --i) update(root[i+],root[i],,n,a[i].second,);
scanf("%d",&m);
for(int i = ; i <= m; ++i) {
int x,y,w;
scanf("%d%d%d",&x,&y,&w);
int l = , r = n, ans = n;
while(l <= r) {
int md = (l+r)>>;
int ss = query(root[md],,n,x,y);
if(ss >= w) l = md+,ans=md;
else r = md - ;
}
printf("%d\n",a[ans].first);
}
return ;
}
Codeforces Round #276 (Div. 1) E. Sign on Fence 二分+主席树的更多相关文章
- CF&&CC百套计划4 Codeforces Round #276 (Div. 1) E. Sign on Fence
http://codeforces.com/contest/484/problem/E 题意: 给出n个数,查询最大的在区间[l,r]内,长为w的子区间的最小值 第i棵线段树表示>=i的数 维护 ...
- Codeforces Round #276 (Div. 1) E. Sign on Fence (二分答案 主席树 区间合并)
链接:http://codeforces.com/contest/484/problem/E 题意: 给你n个数的,每个数代表高度: 再给出m个询问,每次询问[l,r]区间内连续w个数的最大的最小值: ...
- Codeforces Round #365 (Div. 2) C - Chris and Road 二分找切点
// Codeforces Round #365 (Div. 2) // C - Chris and Road 二分找切点 // 题意:给你一个凸边行,凸边行有个初始的速度往左走,人有最大速度,可以停 ...
- 【CF484E】Sign on Fence(主席树)
[CF484E]Sign on Fence(主席树) 题面 懒得贴CF了,你们自己都找得到 洛谷 题解 这不就是[TJOI&HEOI 排序]那题的套路吗... 二分一个答案,把大于答案的都变成 ...
- Codeforces Round #276 (Div. 1) D. Kindergarten dp
D. Kindergarten Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/problemset/proble ...
- Codeforces Round #276 (Div. 1) B. Maximum Value 筛倍数
B. Maximum Value Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/484/prob ...
- Codeforces Round #276 (Div. 1) A. Bits 二进制 贪心
A. Bits Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/484/problem/A Des ...
- Codeforces Round #276 (Div. 2) 解题报告
题目地址:http://codeforces.com/contest/485 A题.Factory 模拟.判断是否出现循环,如果出现,肯定不可能. 代码: #include<cstdio> ...
- CF&&CC百套计划4 Codeforces Round #276 (Div. 1) A. Bits
http://codeforces.com/contest/484/problem/A 题意: 询问[a,b]中二进制位1最多且最小的数 贪心,假设开始每一位都是1 从高位i开始枚举, 如果当前数&g ...
随机推荐
- SharePoint更改密码
stsadm –o updatefarmcredentials –userlogin DomainName\UserName -password NewPassword –local 1. 通过管理 ...
- 深入理解 Win32 PE 文件格式
深入理解 Win32 PE 文件格式 Matt Pietrek 这篇文章假定你熟悉C++和Win32. 概述 理解可移植可执行文件格式(PE)可以更好地了解操作系统.如果你知道DLL和EXE中都有些什 ...
- 进程&线程 同步异步&阻塞非阻塞
2015-08-19 15:23:38 周三 线程 线程安全 如果你的代码所在的进程中有多个线程在同时运行,而这些线程可能会同时运行这段代码 线程安全问题都是由全局变量及静态变量引起的 若每个线程中对 ...
- selenium使用actions.moveToElement处理菜单
//should set firefox path //FirefoxBinary binary=new FirefoxBinary(new File("C:\\Program Files ...
- codeforces 510B. Fox And Two Dots 解题报告
题目链接:http://codeforces.com/problemset/problem/510/B 题目意思:给出 n 行 m 列只有大写字母组成的字符串.问具有相同字母的能否组成一个环. 很容易 ...
- web开发,关于jsp的常见问题,重复提交,防止后退。
看了网上的,有几种方法:1 在你的表单页里HEAD区加入这段代码: <META HTTP-EQUIV="pragma" CONTENT="no-cache" ...
- oracle一条sql语句统计充值表中今天,昨天,前天三天充值记录
select NVL(sum(case when create_date_time>=to_date('2014-11-24 00:00:00','yyyy-mm-dd hh24:mi:ss') ...
- delphi 控件大全(确实很全)
delphi 控件查询:http://www.torry.net/ http://www.jrsoftware.org Tb97 最有名的工具条(ToolBar)控件库,仿Office97,如TDoC ...
- ubuntu下deb包的安装方法
ubuntu下deb包的安装方法 简介 deb是debian linus的安装格式,跟red hat的rpm非常相似,最基本的安装命令是:dpkg -i file.deb dpkg 是Debian P ...
- August 8th 2016, Week 33rd Monday
Everything is going on, but don't give up trying. 万事随缘,但不要放弃努力. Every time when I want to give up, y ...