POJ 2828 Buy Tickets 线段树

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我是靠谱客的博主开放往事，最近开发中收集的这篇文章主要介绍POJ 2828 Buy Tickets 线段树，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

Buy Tickets

Time Limit: 4000MS		Memory Limit: 65536K
Total Submissions: 16992		Accepted: 8411

Description

Railway tickets were difficult to buy around the Lunar New Year in China, so we must get up early and join a long queue…

The Lunar New Year was approaching, but unluckily the Little Cat still had schedules going here and there. Now, he had to travel by train to Mianyang, Sichuan Province for the winter camp selection of the national team of Olympiad in Informatics.

It was one o’clock a.m. and dark outside. Chill wind from the northwest did not scare off the people in the queue. The cold night gave the Little Cat a shiver. Why not find a problem to think about? That was none the less better than freezing to death!

People kept jumping the queue. Since it was too dark around, such moves would not be discovered even by the people adjacent to the queue-jumpers. “If every person in the queue is assigned an integral value and all the information about those who have jumped the queue and where they stand after queue-jumping is given, can I find out the final order of people in the queue?” Thought the Little Cat.

Input

There will be several test cases in the input. Each test case consists of N + 1 lines where N (1 ≤ N ≤ 200,000) is given in the first line of the test case. The next N lines contain the pairs of values Pos_i and Val_i in the increasing order of i (1 ≤ i ≤ N). For each i, the ranges and meanings ofPos_i and Val_i are as follows:

Pos_i ∈ [0, i − 1] — The i-th person came to the queue and stood right behind the Pos_i-th person in the queue. The booking office was considered the 0th person and the person at the front of the queue was considered the first person in the queue.
Val_i ∈ [0, 32767] — The i-th person was assigned the value Val_i.

There no blank lines between test cases. Proceed to the end of input.

Output

For each test cases, output a single line of space-separated integers which are the values of people in the order they stand in the queue.

Sample Input

Sample Output

77 33 69 51
31492 20523 3890 19243

Hint

The figure below shows how the Little Cat found out the final order of people in the queue described in the first test case of the sample input.

Source

POJ Monthly--2006.05.28, Zhu, Zeyuan

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排队问题：

倒着插入保证插入的顺序

更新的时候

若左子树的空格数大于等于要放入的位置，则搜索左子树；

否则，搜索右子树，由于左边有一些空位置，只需要搜索

右子树的部分空位置，使左右空位置之和为要搜索的位置。

大半个月么没做题了

ACcode：

#pragma warning(disable:4786)//使命名长度不受限制
#pragma comment(linker, "/STACK:102400000,102400000")//手工开栈
#include <map>
#include <set>
#include <queue>
#include <cmath>
#include <stack>
#include <cctype>
#include <cstdio>
#include <cstring>
#include <stdlib.h>
#include <iostream>
#include <algorithm>
#define rd(x) scanf("%d",&x)
#define rd2(x,y) scanf("%d%d",&x,&y)
#define rds(x) scanf("%s",x)
#define rdc(x) scanf("%c",&x)
#define ll long long int
#define maxn 200100
#define mod 1000000007
#define INF 0x3f3f3f3f //int 最大值
#define FOR(i,f_start,f_end) for(int i=f_start;i<=f_end;++i)
#define MT(x,i) memset(x,i,sizeof(x))
#define PI  acos(-1.0)
#define E  exp(1)
using namespace std;
int  num[maxn<<2],ans[maxn<<2];
int pos[maxn],val[maxn];
void creatTree(int st,int l,int r){
    if(l==r){
        num[st]=1;
        return;
    }
    int m=(l+r)>>1;
    int temp=st<<1;
    creatTree(temp,l,m);
    creatTree(temp+1,m+1,r);
    num[st]=num[temp]+ num[temp+1];
}
void update(int pos,int val,int st,int l,int r){
    if(l==r){
        ans[l]=val;
        num[st]=0;
        return;
    }
    int temp=st<<1;
    int m=(l+r)>>1;
    if(num[temp]>=pos)update(pos,val,temp,l,m);
    else update(pos-num[temp],val,temp+1,m+1,r);
    num[st]=num[temp]+ num[temp+1];
}
int main(){
    int n;
    while(rd(n)!=EOF){
        FOR(i,1,n)rd2(pos[i],val[i]);
        creatTree(1,1,n);
        MT(ans,0);
        for(int i=n;i>0;i--)
            update(pos[i]+1,val[i],1,1,n);
        FOR(i,1,n)printf("%d ",ans[i]);
        printf("n");
    }
    return 0;
}

/*
4
0 77
1 51
1 33
2 69
4
0 20523
1 19243
1 3890
0 31492
*/