Codeforces Round #361 (Div. 2) D. Friends and Subsequences (二分+RMQ)
来源:互联网 发布:扫描二维码抽奖软件 编辑:程序博客网 时间:2024/05/16 00:41
Mike and !Mike are old childhood rivals, they are opposite in everything they do, except programming. Today they have a problem they cannot solve on their own, but together (with you) — who knows?
Every one of them has an integer sequences a andb of length n. Being given a query of the form of pair of integers(l, r), Mike can instantly tell the value of while !Mike can instantly tell the value of.
Now suppose a robot (you!) asks them all possible different queries of pairs of integers(l, r) (1 ≤ l ≤ r ≤ n) (so he will make exactlyn(n + 1) / 2 queries) and counts how many times their answers coincide, thus for how many pairs is satisfied.
How many occasions will the robot count?
The first line contains only integer n (1 ≤ n ≤ 200 000).
The second line contains n integer numbersa1, a2, ..., an ( - 109 ≤ ai ≤ 109) — the sequence a.
The third line contains n integer numbersb1, b2, ..., bn ( - 109 ≤ bi ≤ 109) — the sequence b.
Print the only integer number — the number of occasions the robot will count, thus for how many pairs is satisfied.
61 2 3 2 1 46 7 1 2 3 2
2
33 3 31 1 1
0
The occasions in the first sample case are:
1.l = 4,r = 4 sincemax{2} = min{2}.
2.l = 4,r = 5 sincemax{2, 1} = min{2, 3}.
There are no occasions in the second sample case since Mike will answer 3 to any query pair, but !Mike will always answer 1.
题意:给你两个数列A,B,问你有多少组区间[l,r]满足其在A中的最大值等于B中的最小值。
分析:枚举区间的起始位置,通过简单分析可以得出,以l为起点的所求区间的r必定是连续的一段,且这段长度内的max = min,事先RMQ处理一下,随后二分出左右端点记入答案。
#include <cstdio>#include <queue> #include <vector> #include <cstdio> #include <utility> #include <cstring> #include <iostream> #include <algorithm> #define INF 0x3f3f3f3fusing namespace std;long long ans;int n,a[200007],b[200007];int Fma[200007][20];int Fmi[200007][20];int qumax(int l,int r){int leng = log2(r-l+1);return max(Fma[l][leng],Fma[r-(1 << leng)+1][leng]);}int qumin(int l,int r){int leng = log2(r-l+1);return min(Fmi[l][leng],Fmi[r-(1 << leng)+1][leng]);}int main(){scanf("%d",&n);for(int i = 1;i <= n;i++) scanf("%d",&a[i]);for(int i = 1;i <= n;i++) scanf("%d",&b[i]);for(int i = 1;i <= n;i++){Fma[i][0] = a[i];Fmi[i][0] = b[i];}for(int i = 1;(1 << i) <= n;i++) for(int j = 1;j + (1 << i) -1 <= n;j++) {Fma[j][i] = max(Fma[j][i-1],Fma[j+(1 << (i-1))][i-1]);Fmi[j][i] = min(Fmi[j][i-1],Fmi[j+(1 << (i-1))][i-1]); }for(int i = 1;i <= n;i++){int s = i;int t = n;while(s != t){ int mid = (s+t)/2;if(qumax(i,mid) >= qumin(i,mid)) t = mid;else s = mid+1;}if(qumax(i,s) != qumin(i,s)) continue;int l = s;s = i,t = n;while(s != t){ int mid = (s+t)/2+1;if(qumax(i,mid) <= qumin(i,mid)) s = mid;else t = mid-1;}int r = s;ans += r-l+1ll;} cout<<ans<<endl;}
- Codeforces Round #361 (Div. 2) D. Friends and Subsequences (二分+RMQ)
- Codeforces Round #361 (Div. 2) D. Friends and Subsequences 二分
- Codeforces Round #361 (Div. 2) D. Friends and Subsequences
- Codeforces Round #361 (Div. 2)D. Friends and Subsequences
- Codeforces Round #361 (Div. 2) D Friends and Subsequences
- Codeforces Round #361 (Div. 2) D Friends and Subsequences
- Codeforces 689D Friends and Subsequences(二分+RMQ)
- Codeforces 689D Friends and Subsequences(二分+RMQ)
- Codeforces 689D Friends and Subsequences(RMQ+二分)
- Codeforces 689D Friends and Subsequences (RMQ+二分)
- Codeforces 689D Friends and Subsequences(二分+RMQ)
- Cf Round #361 (Div. 2) 689D. Friends and Subsequences
- CF 361 D. Friends and Subsequences (RMQ+二分查找)
- codeforces Round #361 D. Friends and Subsequences (ST表,二分)
- Codeforces 689D Friends and Subsequences【思维+二分+RMQ】套路题
- Codeforces Round #361 (Div. 2) D RMQ+二分
- RMQ+二分 - CF 689D Friends and Subsequences
- [Codeforces 689D] Friends and Subsequences (二分+稀疏表)
- JVM 方法内联
- c++教程(三:Variables and types)
- iOS如何将外部数据库放到xcode工程中使用
- 010——hibernate具体表继承:每个子类一个表
- 线程基础
- Codeforces Round #361 (Div. 2) D. Friends and Subsequences (二分+RMQ)
- JavaScript的onkeypress键盘事件
- leetcode题解日练--2016.7.18
- Linux系统下 安装nginx时出现提示的错误:configure: error: You need a C++ compiler for C++ support.
- python核心编程学习笔记-2016-07-18-02-enumerate()函数
- git push 避免重复输入用户名和密码
- HTTP 204和205的应用
- tomcat安全加固指南--SSL通信原理及Tomcat SSL双向验证配置
- mysql记录 第二天