状态压缩/Bitmask 在动态规划问题中,我们会遇到需要记录一个节点是否被占用/是否到达过的情况.而对于一个节点数有多个甚至十几个的问题,开一个巨型的[0/1]数组显然不现实.于是就引入了状态压缩,用一个整数的不同二进制位来表示该节点的状态. Description Given a simple graph, output the number of simple cycles in it. A simple cycle is a cycle with no repeated vertices
Corn Fields Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 9806 Accepted: 5185 Description Farmer John has purchased a lush new rectangular pasture composed of M by N (1 ≤ M ≤ 12; 1 ≤ N ≤ 12) square parcels. He wants to grow some yumm
B. Preparing Olympiad You have n problems. You have estimated the difficulty of the i-th one as integer ci. Now you want to prepare a problemset for a contest, using some of the problems you've made. A problemset for the contest must consist of at le
题意:给出一个n行m列的草地,1表示肥沃,0表示贫瘠,现在要把一些牛放在肥沃的草地上,但是要求所有牛不能相邻,问你有多少种放法. 分析:假如我们知道第 i-1 行的所有的可以放的情况,那么对于第 i 行的可以放的一种情况,我们只要判断它和 i - 1 行的所有情况的能不能满足题目的所有牛不相邻,如果有种中满足,那么对于 i 行的这一中情况有 x 中放法. 但是我们又发现,状态是一种放法,不是我们平常dp的简单的状态,所以要用状态压缩! dp[i][j]表示第i行状态为j的个数. dp
Corn Fields Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 4739 Accepted: 2506 Description Farmer John has purchased a lush new rectangular pasture composed of M by N (1 ≤ M ≤ 12; 1 ≤ N ≤ 12) square parcels. He wants to grow some yumm
SRM 513 2 1000CutTheNumbers Problem Statement Manao has a board filled with digits represented as String[] board. The j-th character of the i-th element of board represents the digit written in cell in row i, column j of the board. The rows are numbe
HDU 5418 Victor and World Time Limit:2000MS Memory Limit:131072KB 64bit IO Format:%I64d & %I64u After trying hard for many years, Victor has finally received a pilot license. To have a celebration, he intends to buy himself an airplane and fl