Redraw Beautiful Drawings Time Limit: 3000/1500 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Problem Description Alice and Bob are playing together. Alice is crazy about art and she has visited many museums around the world. She has…

题目 Source http://acm.hdu.edu.cn/showproblem.php?pid=4888 Description Alice and Bob are playing together. Alice is crazy about art and she has visited many museums around the world. She has a good memory and she can remember all drawings she has seen.…

题意:给定n*m个格子,每个格子能填0-k 的整数.然后给出每列之和和每行之和,问有没有解,有的话是不是唯一解,是唯一解输出方案. 思路:网络流,一共 n+m+2个点   源点 到行连流量为 所给的 当前行之和.    每行 连到每一列 一条流量为  k的边,每列到汇点连 列和.如果流量等于总和则有解,反之无解(如果列总和不等于行总和也无解).  判断方案是否唯一 找残留网络是否存在长度大于2的环即可,有环说明不唯一. #include<cstdio> #include<cstring&…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4888 题意:给一个矩阵没行的和和每列的和,问能否还原矩阵,如果可以还原解是否唯一,若唯一输出该矩阵. 思路:设一个源点和汇点,每行的和和源点加边,权值为该行的和,每列的和和汇点加点,权值为该列的和. 每行和每列加边, 权值为k,跑最大流,如果满流(从源点流出的等于流入汇点的)则证明可以还原该矩阵.   判断是否有多节,就dfs搜,看残余网络中是否有环,无环则解唯一. AC代码: #include<i…

hdu4888 Redraw Beautiful Drawings Time Limit: 3000/1500 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 2007    Accepted Submission(s): 447 Problem Description Alice and Bob are playing together. Alice is crazy abou…

Redraw Beautiful Drawings Time Limit: 3000/1500 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 2909 Accepted Submission(s): 942 Problem Description Alice and Bob are playing together. Alice is crazy about art and she h…

Problem Description Alice and Bob are playing together. Alice is crazy about art and she has visited many museums around the world. She has a good memory and she can remember all drawings she has seen. Today Alice designs a game using these drawings…

14更多学校的第二个问题 网络流量   分别以行,列作为结点建图 i行表示的结点到j列表示的结点的流量便是(i, j)的值 跑遍最大流   若满流了便是有解   推断是否unique  就是在残余网络中dfs.走能够添加流量的边,找到环即不唯一 dfs的时候一定要回溯!! .. . #include <cstdio> #include <ctime> #include <cstdlib> #include <cstring> #include <que…

传送门:pid=4888">[HDU]4888 Redraw Beautiful Drawings 题目分析: 比赛的时候看出是个网络流,可是没有敲出来.各种反面样例推倒自己(究其原因是不愿意写暴力推断的).. 首先是简单的行列建边.源点向行建边.容量为该行元素和,汇点和列建边.容量为该列元素和.全部的行向全部的列建边,容量为K. 跑一次最大流.满流则有解,否则无解. 接下来是推断解是否唯一. 这个题解压根没看懂.还是暴力大法好. 最简单的思想就是枚举在一个矩形的四个端点.设A.D为主对角…

点击打开链接 Redraw Beautiful Drawings Time Limit: 3000/1500 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Total Submission(s): 1660    Accepted Submission(s): 357 Problem Description Alice and Bob are playing together. Alice is crazy about…