Problem Description Given a sequence 1,2,3,--N, your job is to calculate all the possible sub-sequences that the sum of the sub-sequence is M. Input Input contains multiple test cases. each case contains two integers N, M( 1 <= N, M <= 1000000000).i…

The sum problem Problem Description Given a sequence 1,2,3,......N, your job is to calculate all the possible sub-sequences that the sum of the sub-sequence is M.   Input Input contains multiple test cases. each case contains two integers N, M( 1 <=…

Problem Description Given a sequence 1,2,3,......N, your job is to calculate all the possible sub-sequences that the sum of the sub-sequence is M.   Input Input contains multiple test cases. each case contains two integers N, M( 1 <= N, M <= 1000000…

传送门 Description Given a sequence 1,2,3,......N, your job is to calculate all the possible sub-sequences that the sum of the sub-sequence is M. Input Input contains multiple test cases. each case contains two integers N, M( 1 <= N, M <= 1000000000).i…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=2058 问题描述 给定一个序列1,2,3,...... N,你的工作是计算所有可能的子序列,其子序列的总和为M. 输入 输入包含多个测试用例. 每个情况包含两个整数N,M(1 <= N,M <= 1000000000).输入以N = M = 0结束. 输出  对于每个测试用例,打印其总和为M的所有可能的子序列.格式显示在下面的示例中.在每个测试用例后打印一个空行. 示例输入 20 10 50 30…

题目: Given a sequence 1,2,3,......N, your job is to calculate all the possible sub-sequences that the sum of the sub-sequence is M. 思路: 刚开始做写了一个尺取法,脑抽的一批.(这几天心情真的是颓的很,连带脑瓜也不好用了,抓紧调整~~~~) 其实可以根据等差数列求和公式求出这个子序列的长度的一个大致的范围为k=sqrt(2*m),然后根据m和k求出首项a1,然后将a1…

题意:给定一个N和M,N表示从1到N的连续序列,让你求在1到N这个序列中连续子序列的和为M的子序列区间. 析:很明显最直接的方法就是暴力,可是不幸的是,由于N,M太大了,肯定会TLE的.所以我们就想能不能优化一下,找一个范围.想到这是一个连续的序列而且是从1开始的,这不就是一个等差数列么,公差是1罢了.由求和公式得Sn = (a1+an) * n / 2;所以说n最大就是sqrt(M*2)(想一想为什么),因为a1+an 一定是大于n的.如果我们取区间的和,那么Sn = (ai+aj) * (j…

一个数学问题:copy了别人的博客 #include<cstdio> #include<cstdlib> #include<cmath> int main() { int n,m,i,j; while(~scanf("%d%d",&n,&m)) { for( j=(int)sqrt(2*m); j>=1;j--) { i= (2*m/j-j+1)/2; if((i*2-1+j)*j == 2*m && i+j-1…

解题报告:可以说是一个纯数学题,要用到二元一次和二元二次解方程,我们假设[a,b]这个区间的所有的数的和是N,由此,我们可以得到以下公式: (b-a+1)*(a+b) / 2 = N;很显然,这是一个二元一次方程,如果可以解出这个方程里的a,b就可以了,N是已知的,那么可以怎么一个公式怎么解二元方程呢?这里有两种方法可以选择,第一种是可以枚举a = 1,2,3.....,一直枚举到N/2,a是不可能大于N/2,这个你可以自己证明一下,但是这样做的缺点就是数据量还是太大了,N/2任然达到了10的八…

The sum problem Time Limit: 5000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 31453    Accepted Submission(s): 9414 Problem Description Given a sequence 1,2,3,......N, your job is to calculate all the possib…

Sum Problem Time Limit: 1000/500 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 338086    Accepted Submission(s): 85117 Problem Description Hey, welcome to HDOJ(Hangzhou Dianzi University Online Judge). In this pro…

HDOJ(HDU).1258 Sum It Up (DFS) [从零开始DFS(6)] 点我挑战题目 从零开始DFS HDOJ.1342 Lotto [从零开始DFS(0)] - DFS思想与框架/双重DFS HDOJ.1010 Tempter of the Bone [从零开始DFS(1)] -DFS四向搜索/奇偶剪枝 HDOJ(HDU).1015 Safecracker [从零开始DFS(2)] -DFS四向搜索变种 HDOJ(HDU).1016 Prime Ring Problem (DF…

题目传送门 /* 题意:题目讲的很清楚:When n=123 and t=3 then we can get 123->1236->123612->12361215.要求t次操作后,能否被11整除 同余模定理:每次操作将后缀值加到上次操作的值%11后的后面,有点绕,纸上模拟一下就行了 */ /************************************************ * Author :Running_Time * Created Time :2015-8-12 8…

I found summary of k Sum problem and solutions in leetcode on the Internet. http://www.sigmainfy.com/blog/summary-of-ksum-problems.html…

https://en.wikipedia.org/wiki/Subset_sum_problem In computer science, the subset sum problem is an important problem in complexity theory and cryptography. The problem is this: given a set (or multiset) of integers, is there a non-empty subset whose…

The sum problem Time Limit: 5000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 12422 Accepted Submission(s): 3757 Problem Description Given a sequence 1,2,3,......N, your job is to calculate all the possible sub…

题目地址:http://acm.hdu.edu.cn/showproblem.php?pid=1024 Problem Description Now I think you have got an AC in Ignatius.L's "Max Sum" problem. To be a brave ACMer, we always challenge ourselves to more difficult problems. Now you are faced with a mor…

We have a lot of ways to solve the maximum subsequence sum problem, but different ways take different time. 1.Brute-force algorithm int maxSubSum1(const vector<int> &a) { int maxSum=0; for(int i=0;i<a.size();i++) for(int j=i;j<a.size();j++…

/* Name: NYOJ--927--The partial sum problem Author: shen_渊 Date: 15/04/17 19:41 Description: DFS,和 NYOJ--1058--dfs--部分和问题 基本一致,递归的i+1注意了,其他没什么 */ #include<cstring> #include<iostream> using namespace std; void dfs(int); ],vis[]; int n,k,sum,fla…

  继续讲故事~~   上次讲到我们的主人公丁丁,用神奇的动态规划法解决了杂货店老板的两个找零钱问题,得到了老板的肯定.之后,他就决心去大城市闯荡了,看一看外面更大的世界.   这天,丁丁刚回到家,他的弟弟小连就拦住了他,"老哥,有个问题想请教你."对于一向数学见长的小连,这次竟然破天荒的来问自己问题,丁丁感到不可思议:他俩一个以计算机见长,一个以数学见长,各自心里都有点小骄傲,不会轻易地向对方问问题.丁丁迟疑了一会儿,慢慢说道:"有什么问题是我们数学小天才解决不了的?&qu…

Sum Problem Sample code : #include <stdio.h> int main() { int i,n; int sum; while(scanf("%d",&n)!=EOF) { sum=; ;i<=n;i++) sum+=i; printf("%d\n\n",sum); } ; }…

题目传送门 /* 题意:求形如(2 3 4) (4 3 2) (2 3 4)的最长长度,即两个重叠一半的回文串 Manacher:比赛看到这题还以为套个模板就行了,因为BC上有道类似的题,自己又学过Manacher算法,结果入坑WA到死 开始写的是判断是否 p[i]-1 <= p[i+p[i]-1]-1,但是没有想到这种情况:5 (5 1) (1 5) (5 1) 1 单靠最长回文半径是不行的,看了网上的解题报告知道,要从极端位置往回挪才行 给我的教训是只会套模板是没用的,要灵活的使用该算法.另…

The partial sum problem 时间限制:1000 ms  |  内存限制:65535 KB 难度:2 描写叙述 One day,Tom's girlfriend give him an array A which contains N integers and asked him:Can you choose some integers from the N integers and the sum of them is equal to K. 输入 There are mul…

http://acm.hdu.edu.cn/showproblem.php?pid=1258 关键点就是一次递归里面一样的数字只能选一次. #include <cstdio> #include <cstring> int n,t; ],c[]; bool flag; void dfs(int k,int sum,int l) { if(sum==t) { ;i<l-;i++) printf("%d+",c[i]); printf(]); flag=; re…

这一套题做错了几次,按理说直接用等差数列求和公式就行了,主要是要考虑一些运算符的结核性问题: 四则运算符(+.-.*./)和求余运算符(%)结合性都是从左到右. 于是,我自己写了一个版本,主要是考虑(n+1)*n始终为偶数,这样就不用担心除以2时的取整问题: #include <stdio.h> int main(void) { int n; __int64 sum = ; while (scanf("%d", &n) != EOF) { sum = ((n + )…

题意很简单就是给你一个N和M,让你求在1-N的那些个子序列的值等于M 首先暴力法不解释,简单超时 再仔细想一想可以想到因为1-N是一个等差数列,可以运用我们曾经学过的只是来解决 假设开始的位置为s,结束的位置为t,那么一定要满足这个等式 (s+t)(t-s+1)=2*m 又因为S和T都是整数,所以左边的括号中每一项都是等式 所以s+t和t-s+1一定是2*m的因式 所以分解因式并带入就可以求出s和t 假设 s+t=a t-s+1=b a*b=2*m 解得 s=(a-b+1)/2 t=(a+b-1…

因为是circle sequence,可以在序列最后+序列前n项(或前k项);利用前缀和思想,预处理出前i个数的和为sum[i],则i~j的和就为sum[j]-sum[i-1],对于每个j,取最小的sum[i-1],这就转成一道单调队列了,维护k个数的最小值. ---------------------------------------------------------------------------------- #include<cstdio> #include<deque&…

Problem Description Hey, welcome to HDOJ(Hangzhou Dianzi University Online Judge). In this problem, your task is to calculate SUM(n) = 1 + 2 + 3 + ... + n. Input The input will consist of a series of integers n, one integer per line. Output For each…

Problem Description A ring is compose of n circles as shown in diagram. Put natural number 1, 2, ..., n into each circle separately, and the sum of numbers in two adjacent circles should be a prime. Note: the number of first circle should always be 1…

A + B Problem II Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 242959    Accepted Submission(s): 46863 Problem Description I have a very simple problem for you. Given two integers A and B, you…