题目大意: 给定一个元素的值只有1或者0的矩阵,每次可以交换两行(列),问有没有方案使得对角线上的值都是1.题目没有限制需要交换多少次,也没限制行交换或者列交换,也没限制是主对角线还是副对角线.虽然没限制,但是解法都是差不多的. 这是09年的多校题目,对一般人来说,不看解题报告是无法做出来的.我是那种看了解题报告也没做出来,然后看了好几遍才看懂的人. http://www.cnblogs.com/jzlikewei/archive/2012/07/09/2583608.html 解题思路: 对于…

题目链接:https://vjudge.net/problem/HDU-2819 Swap Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 4003    Accepted Submission(s): 1478Special Judge Problem Description Given an N*N matrix with each…

Swap Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 5728    Accepted Submission(s): 2157Special Judge Problem Description Given an N*N matrix with each entry equal to 0 or 1. You can swap any t…

分析:将行和列缩点,即行对应二分图的X部,列对应二分图的Y部,然后交点为连接该行和该列的一条边.匹配时每点都会把整行整列占了,因此就不会出现冲突了. 传送门:hdu1281 棋盘游戏 #include <cstdio> #include <cstring> #include <string> #include <cmath> #include <iostream> #include <algorithm> #include <q…

Swap Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 3371    Accepted Submission(s): 1235 Special Judge Problem Description Given an N*N matrix with each entry equal to 0 or 1. You can swap any…

题目链接:https://cn.vjudge.net/problem/HDU-2819 Given an N*N matrix with each entry equal to 0 or 1. You can swap any two rows or any two columns. Can you find a way to make all the diagonal entries equal to 1? InputThere are several test cases in the in…

SwapTime Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3102 Accepted Submission(s): 1117Special Judge Problem DescriptionGiven an N*N matrix with each entry equal to 0 or 1. You can swap any two rows…

Given an N*N matrix with each entry equal to 0 or 1. You can swap any two rows or any two columns. Can you find a way to make all the diagonal entries equal to 1? InputThere are several test cases in the input. The first line of each test case is an…

Swap Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3800    Accepted Submission(s): 1401Special Judge Problem Description Given an N*N matrix with each entry equal to 0 or 1. You can swap any t…

题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=2819 题目大意:给你一个n*n的01矩阵,问是否可以通过任意交换整行或者整列使得正对角线上都是1. 解题思路: 按行列建图,求最大匹配,若最大匹配数<n,则肯定无解(矩阵的秩要等于n才有解).若有解,则肯定可以通过只交换行或者交换列得到.所以我们从i=1 to n检查link[i]=i(link[i]表示第i列的1对应的行号)是否成立,否则找到link[j]=i交换link[i]和link[j]并…