题面 Farmer John's owns N cows (2 <= N <= 20), where cow i produces M(i) units of milk each day (1 <= M(i) <= 100,000,000). FJ wants to streamline the process of milking his cows every day, so he installs a brand new milking machine in his barn.…

题意 给定一个集合,有多少个非空子集,能划分成和相等的两份.\(n\leq 20\) 题解 看到这个题,首先能想到的是\(3^n\)的暴力枚举,枚举当前元素是放入左边还是放入右边或者根本不放,但是显然是不可取的,看到\(n\)只有20,考虑折半搜索,将集合分成两部分,每个部分\(3^{\frac{n}{2}}\)枚举. 接着考虑如何合并,在枚举时计一个\(delta\)表示此时左边和右边的差值,这样在右半部分每一次枚举完后我们可以直接在左半部分查找是否存在一个\(delta\)相等,如果相等,则…

Given a non-empty array containing only positive integers, find if the array can be partitioned into two subsets such that the sum of elements in both subsets is equal. Note: Both the array size and each of the array element will not exceed 100. Exam…

Given a set of distinct positive integers, find the largest subset such that every pair (Si, Sj) of elements in this subset satisfies: Si % Sj = 0 or Sj % Si = 0. If there are multiple solutions, return any subset is fine. Example 1: nums: [1,2,3] Re…

题目描述 对于从1到N (1 <= N <= 39) 的连续整数集合,能划分成两个子集合,且保证每个集合的数字和是相等的.举个例子,如果N=3,对于{1,2,3}能划分成两个子集合,每个子集合的所有数字和是相等的: {3} 和 {1,2} 这是唯一一种分法(交换集合位置被认为是同一种划分方案,因此不会增加划分方案总数) 如果N=7,有四种方法能划分集合{1,2,3,4,5,6,7},每一种分法的子集合各数字和是相等的: {1,6,7} 和 {2,3,4,5} {注 1+6+7=2+3+4+5}…

Very nice DP problem. The key fact of a mutual-divisible subset: if a new number n, is divisible with the largest number m within a mutual-divisible set s, s U {n} is also a mutal-divisible subset. class Solution { public: vector<int> largestDivisib…

N (1 <= N <= 39),问有多少种把1到N划分为两个集合的方法使得两个集合的和相等. 如果总和为奇数,那么就是0种划分方案.否则用dp做. dp[i][j]表示前 i 个数划分到一个集合里,和为j的方法数. dp[i][j]=dp[i-1][j]+dp[i][j-i] n 为 39 时,1 到 39 的和为 780,枚举 j 的时候枚举到 s/2,最后输出dp[n][s/2]/2. http://train.usaco.org/usacoprob2?a=z5hb7MFUmsX&…

Given a non-empty array containing only positive integers, find if the array can be partitioned into two subsets such that the sum of elements in both subsets is equal. Note: Each of the array element will not exceed 100. The array size will not exce…

Given a set of distinct positive integers, find the largest subset such that every pair (Si, Sj) of elements in this subset satisfies: Si % Sj = 0 or Sj % Si = 0. If there are multiple solutions, return any subset is fine. Example 1: nums: [1,2,3] Re…

制图工作中,大量密集点显示是最常遇到的问题.其特点是分布可能不均匀.数据点比较密集,容易造成空间上的重叠,影响制图美观.那么,如果美观而详细的显示制图呢? Subset Features(子集要素)工具是 ArcGIS 地统计分析模块的一个工具,该工具可将数据按照百分比进行抽稀,生成两个结果数据集,一个是抽稀后保留的数据,另一个是互补的那一部分数据. 实现原理 其原理是将数据分成两个子集.子集 1 将有 L 个要素,子集 2 将有 N - L 个要素(N 表示原始数据集中的要素数量).要素的分割…