Problem Description sevenzero liked Warcraft very much, but he haven't practiced it for several years after being addicted to algorithms. Now, though he is playing with computer, he nearly losed and only his hero Pit Lord left. sevenzero is angry, he…

最基础的dancing links的精确覆盖题目 #include <iostream> #include <cstring> #include <cstdio> #include <algorithm> using namespace std; #define N 1005 #define MAXN 1000100 struct DLX{ int n , m , size;//size表示当前dlx表中有多少个元素 int ans[N] , k;//ans…

题目链接:https://vjudge.net/problem/HUST-1017 1017 - Exact cover 时间限制:15秒 内存限制:128兆 自定评测 7673 次提交 3898 次通过 题目描述 There is an N*M matrix with only 0s and 1s, (1 <= N,M <= 1000). An exact cover is a selection of rows such that every column has a 1 in exact…

hihoCoder #1317 : 搜索四·跳舞链 原题地址:http://hihocoder.com/problemset/problem/1317 时间限制:10000ms 单点时限:1000ms 内存限制:256MB   描述 小Ho最近遇到一个难题,他需要破解一个棋局. 棋局分成了n行,m列,每行有若干个棋子.小Ho需要从中选择若干行使得每一列有且恰好只有一个棋子. 比如下面这样局面: 其中1表示放置有棋子的格子,0表示没有放置棋子. 对于上面这个问题,小Ho经过多次尝试以后得到了解为选…

DLX的题,做过这题才算是会吧. 这道题转化成了精确覆盖模型来做,一开始,只是单纯的要覆盖完行列和斜线,WA. 后来醒悟了,不能这样,只要覆盖全部行或列即可.虽然如此,但某些细节地方很关键不能考虑到. 特别要注意的是 for(int i=R[c];i;i=R[i]){ if(i>ne) break; if(S[i] < S[c]) c = i;} 找最小值只能是在ne之前,为什么呢?因为我们要完全覆盖行.可行吗?可行.稍微留意一下DLX的模板就知道,它其实在选中一列之后,是会枚举列上的行值,…

1017 - Exact cover 时间限制:15秒 内存限制:128兆 自定评测 5584 次提交 2975 次通过 题目描述 There is an N*M matrix with only 0s and 1s, (1 <= N,M <= 1000). An exact cover is a selection of rows such that every column has a 1 in exactly one of the selected rows. Try to find o…

题意: 给你n块碎片,这些碎片不能旋转.翻折. 问你能不能用当中的某些块拼出4*4的正方形. 思路: 精确覆盖裸题了 建图就是看看每一个碎片在4*4中能放哪些位置,这个就作为行. 列就是4*4=16个位置再加上n个碎片也就是16+n 然后注意下成立的判定就好了 代码: #include"stdio.h" #include"algorithm" #include"string.h" #include"iostream" #inc…

DLX精确覆盖.....模版题 Sudoku Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 8336   Accepted: 2945 Description In the game of Sudoku, you are given a large 9 × 9 grid divided into smaller 3 × 3 subgrids. For example, . 2 7 3 8 . . 1 . . 1 . .…

数独问题,输入谜题,输出解 既然都把重复覆盖的给写成模板了,就顺便把精确覆盖的模板也写好看点吧...赤裸裸的精确覆盖啊~~~水一水~~~然后继续去搞有点难度的题了... #include <cstdio> #include <cstring> #include <iostream> #include <algorithm> #include <cmath> #include <string> #include <vector&g…

题目链接 精确覆盖的模板题, 把每一个格子当成一列就可以. S忘记初始化TLE N次, 哭晕在厕所...... #include<bits/stdc++.h> using namespace std; #define pb(x) push_back(x) #define ll long long #define mk(x, y) make_pair(x, y) #define lson l, m, rt<<1 #define mem(a) memset(a, 0, sizeof(a…