题目链接:hdu 3410 Passing the Message 题意: 说那么多,其实就是对于每个a[i],让你找他的从左边(右边)开始找a[j]<a[i]并且a[j]=max(a[j])(k+1<j<i),a[k]>a[i]. 题解: 从左往右维护一个递减的单调队列,每次都从尾巴开始把比a[i]的踢掉,最后踢的那个就是答案. 右边同理. #include<bits/stdc++.h> #define F(i,a,b) for(int i=a;i<=b;i++…

题意: 给定n长的数组(下标从1-n)(n个人的身高,身高各不同样 问:对于第i个人,他能看到的左边最矮的人下标.(假设这个最矮的人被挡住了,则这个值为0) 还有右边最高的人下标,同理若被挡住了则这个值为0 输出n行,每一个人左右2边的下标. 单调队列,对于 front - rear 的队列(注意出队都是在rear,入队也是在rear) 当增加元素x,若这队列是单调递增的,显然q.front() <= x , 反之若>x ,则把队首元素弹掉,这样就能保持单调性. 若弹掉了队首元素,在此题中就相…

Passing the Message What a sunny day! Let’s go picnic and have barbecue! Today, all kids in “Sun Flower” kindergarten are prepared to have an excursion. Before kicking off, teacher Liu tells them to stand in a row. Teacher Liu has an important messag…

可以先处理出每个a[i]最左和最右能到达的位置,L[i],和R[i].然后就只要询问区间[ L[i],i-1 ]和区间[ i+1,R[i] ]最大值位置即可. #include<cstdio> #include<cstring> #include<cmath> #include<algorithm> #include<vector> #include<map> #include<set> #include<queue…

题目链接:hdu 5945 Fxx and game 题意: 让你从x走到1的位置,问你最小的步数,给你两种走的方式,1.如果k整除x,那么你可以从x走一步到k.2.你可以从x走到j,j+t<=x 题解: 看这个数据规模,多半要用O(N)的做法,比赛的时候我当时用的贪心,但这肯定是错的,最终FST了,当时不会单调队列. 我们设dp[i],表示走到i的最小步数,那么就有dp[i]=min{dp[i/k](k|i),dp[j]+1(j+t<=x)}. 对于第一项,我们直接判断一下就行了,对于第二项…

Description Panagola, The Lord of city F likes to parade very much. He always inspects his city in his car and enjoys the welcome of his citizens. City F has a regular road system. It looks like a matrix with n+1 west-east roads and m+1 north-south r…

题目传送门//res tp hdu 维护递增单调队列 根据数据范围推测应为O(n)的. 我们需要维护一个区间的信息,区间内信息是"有序"的,同时需要在O(1)的时间进行相邻区间的信息转移. 若是主数列从头到尾转移无法有解题突破口,就反过来从尾到头再思考. #include<iostream> #include<cstdio> #include<algorithm> #include<cstring> #define rep(i,a,b)…

题目链接: Assignment  题意: 给出一个数列,问其中存在多少连续子序列,使得子序列的最大值-最小值<k. 题解: RMQ先处理出每个区间的最大值和最小值(复杂度为:n×logn),相当于求出了每个区间的最大值-最小值.那么现在我们枚举左端点,二分右端点就可以在n×logn×logn的时间内过. #include<bits/stdc++.h> using namespace std; ; int vec[MAX_N]; ]; ]; ; int N,M,T; void ST(in…

Tom owns a company and he is the boss. There are n staffs which are numbered from 1 to n in this company, and every staff has a ability. Now, Tom is going to assign a special task to some staffs who were in the same group. In a group, the difference…

题意:给定一个序列,让你构造出一个序列,满足条件,且最大.条件是 选取一个ai <= max{a[b[j], j]-j} 析:贪心,贪心策略就是先尽量产生大的,所以就是对于B序列尽量从头开始,由于数据比较大,采用桶排序,然后维护一个单调队列,使得最头上最大. 代码如下: #pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string> #i…