题目链接:https://cn.vjudge.net/contest/276233#problem/H 题目大意:对于给定的矩阵  每一行除以ai  每一列除以bi 之后 数组的所有元素都还在那个L-R范围之内,a[i]和b[j]是不知道的,然后问你是否有这样的数组a和数组b满足条件. 具体思路:我们可以写出这样的等式, L<=Map[i][j]*a[i]/b[j]<=R, 然后继续化简 L/Map[i][j]<=a[i]/b[j]<=R/Map[i][j], 然后两边同时取log…

THE MATRIX PROBLEM Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 8693    Accepted Submission(s): 2246 Problem Description You have been given a matrix CN*M, each element E of CN*M is positive…

题意: 给一个n*m矩阵,每个格子上有一个数字a[i][j],给定L和U,问:是否有这样两个序列{a1...an}和{b1...bn},满足 L<=a[i][j]*ai/bj<=U .若存在输出yes,否则no. 思路: 能够得到的是一堆不等式,那么可以用最短路来解决差分约束系统.但是a[i][j]*ai/bj<=U是除的,得提前变成减的才行.可以用对数log来解决,先不管a[i][j],logai-logbj<=U不就行了?可以得到: (1)logai - logbj<=U…

THE MATRIX PROBLEM Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 7819    Accepted Submission(s): 2019 Problem Description You have been given a matrix CN*M, each element E of CN*M is positive…

THE MATRIX PROBLEM Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 5437    Accepted Submission(s): 1372 Problem Description You have been given a matrix CN*M, each element E of CN*M is positive…

题目: Description 有一个n*m的矩阵,初始每个格子的权值都为0,可以对矩阵执行两种操作: 选择一行, 该行每个格子的权值加1或减1. 选择一列, 该列每个格子的权值加1或减1. 现在有K个限制,每个限制为一个三元组(x,y,c),代表格子(x,y)权值等于c. 问是否存在一个操作序列,使得操作完后的矩阵满足所有的限制.如果存在输出"Yes",否则输出"No". 题解: 如果我们将所有的行作为变量\(x\),所有的列作为变量\(y\). 变量本身代表对这…

https://vjudge.net/problem/UVA-11478 给定一个有向图,每条边都有一个权值.每次你可以选择一个结点v和一个整数d,把所有以v为终点的边的权值减小d,把所有以v为起点的边的权值增加d,最后让所有边的权值的最小值大于零且尽量大. 该死书上翻译错了 >0不是非负 WA好几次因为这个 考虑每条边的约束,di表示i的halum量 w-dv+du>0 dv-du<w 但求解这个差分约束系统只是让这组不等式成立,最长路和最短路控制的都是单个d的最值而不是最小值最大 那…

H. Degenerate Matrix Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/549/problem/H Description The determinant of a matrix 2 × 2 is defined as follows: A matrix is called degenerate if its determinant is equal to zero. The…

THE MATRIX PROBLEM Time Limit: 4000/2000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 41 Accepted Submission(s): 14   Problem Description You have been given a matrix CN*M, each element E of CN*M is positive and no…

Problem  UVA - 11090 - Going in Cycle!! Time Limit: 3000 mSec Problem Description You are given a weighted directed graph with n vertices and m edges. Each cycle in the graph has a weight, which equals to sum of its edges. There are so many cycles in…