http://acm.hdu.edu.cn/showproblem.php? pid=2870 Largest Submatrix Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 1569    Accepted Submission(s): 748 Problem Description Now here is a matrix wi…

Problem Description Now here is a matrix with letter 'a','b','c','w','x','y','z' and you can change 'w' to 'a' or 'b', change 'x' to 'b' or 'c', change 'y' to 'a' or 'c', and change 'z' to 'a', 'b' or 'c'. After you changed it, what's the largest sub…

这三道题的关系是这样的,1505是1506的加强版,2870又是1505的加强版 如果按照上面由简到易的顺序来做的话,还是很简单的 这道题的思想就是 枚举+DP 因为某些字符可以变值,所以我们枚举a, b, c三个矩阵 分别求出对应的h数组以及最大子矩阵,再在里面求出一个最大值即可. //#define LOCAL #include <iostream> #include <cstdio> #include <cstring> #include <algorith…

Largest Submatrix Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 2018    Accepted Submission(s): 967 Problem Description Now here is a matrix with letter 'a','b','c','w','x','y','z' and you ca…

POJ 2796 Feel Good HDU 1506 Largest Rectangle in a Histogram 和这两题一样的方法. #include<cstdio> #include<cstring> #include<cmath> #include<algorithm> using namespace std; +; int a[maxn]; int L[maxn],R[maxn]; int m,n; int tmp[maxn][maxn],b…

Largest Submatrix of All 1’s Time Limit: 5000MS   Memory Limit: 131072K Total Submissions: 8551   Accepted: 3089 Case Time Limit: 2000MS Description Given a m-by-n (0,1)-matrix, of all its submatrices of all 1’s which is the largest? By largest we me…

Given a m-by-n (0,1)-matrix, of all its submatrices of all 1’s which is the largest? By largest we mean that the submatrix has the most elements. Input The input contains multiple test cases. Each test case begins with m and n (1 ≤ m, n ≤ 2000) on li…

codeforces 407D Largest Submatrix 3 题意 找出最大子矩阵,须满足矩阵内的元素互不相等. 题解 官方做法 http://codeforces.com/blog/entry/11333 \(O(n^6)\) 枚举子矩阵,暴力check. \(O(n^4)\) 枚举上下边界,双指针. \(O(n^3log_2n)\) 假设当前上边界 \(up\), 下边界 \(down\),\(R_i\) 表示当 \(i\) 为左边界时,右边界最大是 \(R_i\). 当 \(do…

Given a m-by-n (0,1)-matrix, of all its submatrices of all 1's which is the largest? By largest we mean that the submatrix has the most elements. Input The input contains multiple test cases. Each test case begins with m and n (1 ≤ m, n ≤ 2000) on li…

POJ 3494 Largest Submatrix of All 1’s Description Given a m-by-n (0,1)-matrix, of all its submatrices of all 1’s which is the largest? By largest we mean that the submatrix has the most elements. Input The input contains multiple test cases. Each tes…

Largest Submatrix of All 1’s Given a m-by-n (0,1)-matrix, of all its submatrices of all 1’s which is the largest? By largest we mean that the submatrix has the most elements. Input The input contains multiple test cases. Each test case begins with m …

MINSUB - Largest Submatrix no tags  You are given an matrix M (consisting of nonnegative integers) and an integer K.  For any submatrix of M' of M define min(M') to be the minimum value of all the entries of M'.  Now your task is simple:  find the ma…

Largest Rectangle in a Histogram http://poj.org/problem?id=2559 题意:给出若干宽度相同的矩形的高度(条形统计图),求最大子矩形面积 解题思路 单调栈的经典题(嫌弃字多可以先看后面的示例再来看这个思路) 显然,最终的子矩形高度一定和某一个矩形相等(反证).因此一个暴力的做法就是枚举每一个矩形,然后往两边扩散.在它左侧找到第一个高度比它小的,右侧也一样.则可以求出最大可扩散宽度,乘上高度即可以更新答案.复杂度O(n2) 如果说要优化刚才…

Largest Submatrix Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3105    Accepted Submission(s): 1476 Problem Description Now here is a matrix with letter 'a','b','c','w','x','y','z' and you ca…

Largest Submatrix 3 给出一个\(n\times m\)的网格图,第i行第j列上的格子有数字\(a[i][j]\),显然,你可以从中找到一个子矩阵,保证子矩阵中的数字互不相同,求子矩阵的最大面积,\(n,m\leq 400,a[i][j]\leq 400^2\). 解 法一:确定上下边界+双指针 枚举子矩阵上边界和下边界,发现确定了左端点后,随着左端点的递增,右端点也在递增,于是可以双指针做到\(O(n^4)\). 参考代码: 你来写啊 法二:确定上边界,枚举下边界,维护一个左…

Largest Submatrix of All 1’s Time Limit: 5000MS   Memory Limit: 131072K Total Submissions: 9512   Accepted: 3406 Case Time Limit: 2000MS Description Given a m-by-n (0,1)-matrix, of all its submatrices of all 1’s which is the largest? By largest we me…

Largest Submatrix 给出一个\(n\times m\)的网格,网格里只放有字符a,b,c,d,w,x,,z,现在你可以将其中的w换成a,b,把x换成b,c,把y换成a,c,把z换成a,b,c,询问换完以后最大的子矩阵大小,使其包含一样的字符,\(1 ≤ m, n ≤ 1000\). 解 注意到字符很少,我们可以钦定最大的子矩阵的字符,也就是尽量把字符变成变成所钦定,正确性显然. 于是接下来问题就变成了如何快速找到这个矩阵了,接下来简要提一下做法,如果初学者看不懂可以看一下这道题目…

E - Largest Rectangle in a Histogram Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u Submit Status Practice HDU 1506 Appoint description: Description A histogram is a polygon composed of a sequence of rectangles aligned a…

Largest Rectangle in a Histogram Problem Description: A histogram is a polygon composed of a sequence of rectangles aligned at a common base line. The rectangles have equal widths but may have different heights. For example, the figure on the left sh…

Largest Point Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://acm.hdu.edu.cn/showproblem.php?pid=5461 Description Given the sequence A with n integers t1,t2,⋯,tn. Given the integral coefficients a and b. The fact that select two elements ti and tj…

题目链接:HDU - 1506 A histogram is a polygon composed of a sequence of rectangles aligned at a common base line. The rectangles have equal widths but may have different heights. For example, the figure on the left shows the histogram that consists of rec…

题目网址:http://acm.hdu.edu.cn/showproblem.php?pid=1506 题目: Largest Rectangle in a Histogram Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 18833    Accepted Submission(s): 5636 Problem Description…

Description A histogram is a polygon composed of a sequence of rectangles aligned at a common base line. The rectangles have equal widths but may have different heights. For example, the figure on the left shows the histogram that consists of rectang…

Largest Rectangle in a Histogram Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 11706    Accepted Submission(s): 3219 Problem Description A histogram is a polygon composed of a sequence of rec…

题意:让你求的是由同一字母组成的最大子矩阵,w可以变成a或者b,x可以变成b或者c,y可以变成a或者c,z可以变成a或者b或者c. 分析:这是hdu 1506.hdu 1505的加强版,具体的分析看我的博客:http://www.cnblogs.com/jiangjing/p/3221423.html 代码实现: #include<stdio.h> #include<string.h> #include<stdlib.h> #include<iostream>…

Problem Description Everybody knows any number can be combined by the prime number. Now, your task is telling me what position of the largest prime factor. The position of prime 2 is 1, prime 3 is 2, and prime 5 is 3, etc. Specially, LPF(1) = 0. Inpu…

                                                                                                   Largest Rectangle in a Histogram       A histogram is a polygon composed of a sequence of rectangles aligned at a common base line. The rectangles have…

题目:http://acm.hdu.edu.cn/showproblem.php?pid=1506 关于笛卡尔树的构建:https://www.cnblogs.com/reverymoon/p/9525764.html 笛卡尔树在 key 上满足二叉搜索树,在 value 上满足堆:一般 key 就是原序列里的位置,这样一个子树对应原序列的一段连续区间. 这个构建方法就是给最右链维护单调栈,新进来第 i 个元素之后,根据 value 是堆的规则弹栈,然后把自己的左孩子设成最后弹掉的那个点,把自己…

题目连接: http://acm.hdu.edu.cn/showproblem.php?pid=1506 题目大意: 给出一个数列An,问以Ai为最小值的区间内有多少个元素? 解题思路: 手动模拟一个栈.栈内元素为一个单调不递减序列.当新元素Ai需要进栈,如果栈顶元素大于Ai,弹出栈顶元素,直到栈顶元素不大于Ai,Ai进栈. 这里可以保证i是高为栈顶元素的矩形向后延伸的边界,弹出过程中记录高为Ai的矩阵向前延伸的边界. //#include <bits/stdc++.h> #include &…

Largest Rectangle in a Histogram Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 11137    Accepted Submission(s): 3047 Problem Description A histogram is a polygon composed of a sequence of rec…