Happy Matt Friends Time Limit: 6000/6000 MS (Java/Others)    Memory Limit: 510000/510000 K (Java/Others)Total Submission(s): 1810    Accepted Submission(s): 715 Problem Description Matt has N friends. They are playing a game together. Each of Matt’s…

Happy Matt Friends Time Limit: 6000/6000 MS (Java/Others)    Memory Limit: 510000/510000 K (Java/Others)Total Submission(s): 6164    Accepted Submission(s): 2330 Problem Description Matt has N friends. They are playing a game together. Each of Matt’s…

题意:给定n个数,从中分别取出0个,1个,2个...n个,并把他们异或起来,求大于m个总的取法. 思路:dp,背包思想,考虑第i个数,取或者不取,dp[i][j]表示在第i个数时,异或值为j的所有取法.dp[i][j] = dp[i - 1][j] + dp[i - 1][j ^ a[i]]); 其中dp[i - 1][j]表示不取第i个数,dp[i - 1][j ^ a[i]]表示取第i个数,由于40比较大,所以用滚动数组优化,后一个状态需要前一个来推导,而和前一个之前的所有的没有关系,所以之…

题目链接 题意:n个数,你可以从中选一些数,也可以不选,选出来的元素的异或和大于m时,则称满足情况.问满足情况的方案数为多少. 分析:本来以为是用什么特殊的数据结构来操作,没想到是dp,还好队友很强.定义dp[i][j]为在前i个数里选一些数的异或和为j的方案数,边计算边统计, #include <iostream> #include <cstdio> #include <cstring> typedef long long ll; <<); using n…

题目链接 题意 : 给你n个数,让你从中挑K个数(K<=n)使得这k个数异或的和小于m,问你有多少种异或方式满足这个条件. 思路 : 正解据说是高斯消元.这里用DP做的,类似于背包,枚举的是异或的和,给定的数你可以选择放或者不放,dp[i][j]代表的是前 i 个数中选择k个异或的和为j. #include <stdio.h> #include <string.h> #include <iostream> #define LL long long using na…

Happy Matt Friends Time Limit: 6000/6000 MS (Java/Others) Memory Limit: 510000/510000 K (Java/Others) Total Submission(s): 700 Accepted Submission(s): 270 Problem Description Matt has N friends. They are playing a game together. Each of Matt's friend…

Happy Matt Friends Time Limit: 6000/6000 MS (Java/Others)    Memory Limit: 510000/510000 K (Java/Others)Total Submission(s): 5188    Accepted Submission(s): 1985 Problem Description Matt has N friends. They are playing a game together. Each of Matt’s…

题目链接:HDU 5119 Problem Description Matt has N friends. They are playing a game together. Each of Matt's friends has a magic number. In the game, Matt selects some (could be zero) of his friends. If the xor (exclusive-or) sum of the selected friends'ma…

描述 Matt hzs N friends. They are playing a game together. Each of Matt’s friends has a magic number. In the game, Matt selects some (could be zero) of his friends. If the xor (exclusive-or) sum of the selected friends’magic numbers is no less than M ,…

虽然是一道还是算简单的DP,甚至不用滚动数组也能AC,数据量不算很大. 对于N个数,每个数只存在两个状态,取 和 不取. 容易得出状态转移方程: dp[i][j] = dp[i - 1][j ^ a[i]] + dp[i - 1][j]; dp[i][j] 的意思是,对于数列 中前 i 个数字,使得 XOR 和恰好为 j 的方案数 状态转移方程中的 dp[i - 1][j] 即表示当前这个数字不取, dp[i - 1][j ^ a[i]] 表示当前这个数字要取. 这道题还是要好好理解阿! sou…