Sumsets Description Farmer John commanded his cows to search for different sets of numbers that sum to a given number. The cows use only numbers that are an integer power of 2. Here are the possible sets of numbers that sum to 7: 1) 1+1+1+1+1+1+1 2)…

Sumsets Time Limit: 2000MS   Memory Limit: 200000K Total Submissions: 15045   Accepted: 5997 Description Farmer John commanded his cows to search for different sets of numbers that sum to a given number. The cows use only numbers that are an integer…

Sumsets 直接翻译了 Descriptions Farmer John 让奶牛们找一些数加起来等于一个给出的数N.但是奶牛们只会用2的整数幂.下面是凑出7的方式 1) 1+1+1+1+1+1+1 2) 1+1+1+1+1+2 3) 1+1+1+2+2 4) 1+1+1+4 5) 1+2+2+2 6) 1+2+4 帮助FJ找到 N的分配数 (1 <= N <= 1,000,000). Input N Output 排列方式总数.由于这个数可能很大,只需要保留最后9位 Sample Inpu…

题目大意 给定一个数N,问由不同的2的幂之和能组成N的方法有多少种 题解 看完题目立马想到完全背包...敲完代码上去超时了....后来发现是%的原因...改成减法就A了...%也太他妈耗时了吧!!!(还有一种O(n)的算法...) 代码: #include<stdio.h> #include<string.h> #define MOD 1000000000 #define MAXN 1000005 int dp[MAXN]; int main() { int n; scanf(&q…

discuss 看到有人讲完全背包可以过, 假如我自己做的话, 也只能想到完全背包了 思路: 1. 当 n 为奇数时, f[n] = f[n-1], 因为只需在所有的序列前添加一个 1 即可, 所有的序列同时延迟 1 位, 不会出现重复 若是这个 1 和其他的1组成 2 而不是放在首位, 怎么办? 不会这样, 因为这个序列肯定已经存在了 证明, 假设sum(s1) = 2*k, s1内部某个1加1得到 s2, 则 sum(s2) = 2*k+1, s2 的首位仍然肯定是1, 那么 s2 也可以通…

题目链接:http://www.lydsy.com/JudgeOnline/problem.php?id=1677 题意: 给定n(n <= 10^6),将n分解为2的幂次方之和,问你有多少种方法. 题解: 两种方法. 一.无限背包 将1,2,4,8...看作物品体积就好. 复杂度O(n*k),k约为20. 二.递推 对于dp[i],有两种情况. (1)i为奇数.则分解结果中一定有1. 所以dp[i] = dp[i-1]. (2)i为偶数.再分两种情况: a. 分解结果中有1,所以dp[i] +…

1677: [Usaco2005 Jan]Sumsets 求和 Time Limit: 5 Sec  Memory Limit: 64 MBSubmit: 570  Solved: 310[Submit][Status] Description Farmer John commanded his cows to search for different sets of numbers that sum to a given number. The cows use only numbers th…

完全背包.. --------------------------------------------------------------------------------------- #include<cstdio> #include<algorithm> #include<cstring> #include<iostream>   #define rep( i , n ) for( int i = 0 ; i < n ; i++ ) #defi…

Sumsets Time Limit: 2000MS   Memory Limit: 200000K Total Submissions: 19024   Accepted: 7431 Description Farmer John commanded his cows to search for different sets of numbers that sum to a given number. The cows use only numbers that are an integer…

Sumsets Time Limit: 2000MS   Memory Limit: 200000K Total Submissions: 20315   Accepted: 7930 Description Farmer John commanded his cows to search for different sets of numbers that sum to a given number. The cows use only numbers that are an integer…