题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1003 Max Sum Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 158421    Accepted Submission(s): 37055 Problem Description Given a sequence a[1],a[2]…

Max Sum of Max-K-sub-sequence Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 5690    Accepted Submission(s): 2059 Problem Description Given a circle sequence A[1],A[2],A[3]......A[n]. Circle s…

因为是circle sequence,可以在序列最后+序列前n项(或前k项);利用前缀和思想,预处理出前i个数的和为sum[i],则i~j的和就为sum[j]-sum[i-1],对于每个j,取最小的sum[i-1],这就转成一道单调队列了,维护k个数的最小值. ---------------------------------------------------------------------------------- #include<cstdio> #include<deque&…

DP/单调队列优化 呃……环形链求最大k子段和. 首先拆环为链求前缀和…… 然后单调队列吧<_<,裸题没啥好说的…… WA:为毛手写队列就会挂,必须用STL的deque?(写挂自己弱……sigh) //HDOJ 3415 #include<queue> #include<cmath> #include<vector> #include<cstdio> #include<cstring> #include<cstdlib>…

链接:http://acm.hdu.edu.cn/showproblem.php?pid=3415 意甲冠军:环.要找出当中9长度小于等于K的和最大的子段. 思路:不能採用最暴力的枚举.题目的数据量是10^5,O(N^2)的枚举回去超时.本题採用的非常巧妙的DP做法,是用单调队列优化的DP. 运用的是STL的deque,从i:1~a找到以当中以i为尾的符合条件的子段.并将i本身放入双向队列.全部i从队列后放入,保证了队列的单调性. 代码: #include <iostream> #includ…

Max Sum of Max-K-sub-sequence Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 5084    Accepted Submission(s): 1842 Problem Description Given a circle sequence A[1],A[2],A[3]......A[n]. Circle s…

题目链接:hdu 3415 Max Sum of Max-K-sub-sequence 题意: 给你一串形成环的数,让你找一段长度不大于k的子段使得和最大. 题解: 我们先把头和尾拼起来,令前i个数的和为sum[i]. 然后问题变成了求一个max{sum[i]-sum[j]}(i-k<j<i) 意思就是对于每一个sum[i],我们只需要找一个满足条件的最小的sum[j],然后我们就可以用一个单调队列来维护. #include<bits/stdc++.h> #define F(i,a…

Max Sum of Max-K-sub-sequence Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 5335    Accepted Submission(s): 1939 Problem Description Given a circle sequence A[1],A[2],A[3]......A[n]. Circle se…

Given a non-empty 2D matrix matrix and an integer k, find the max sum of a rectangle in the matrix such that its sum is no larger than k. Example: Given matrix = [ [1, 0, 1], [0, -2, 3] ] k = 2 The answer is 2. Because the sum of rectangle [[0, 1], […

Given a non-empty 2D matrix matrix and an integer k, find the max sum of a rectangle in the matrix such that its sum is no larger than k. Example: Given matrix = [ [1, 0, 1], [0, -2, 3] ] k = 2 The answer is 2. Because the sum of rectangle [[0, 1], […