1142 - Summing up Powers (II)    PDF (English) Statistics Forum Time Limit: 2 second(s) Memory Limit: 32 MB Shanto is learning how to power up numbers and he found an efficient way to find kth power of a matrix. He was quite happy with his discovery.…

题目链接:http://lightoj.com/volume_showproblem.php?problem=1132 题意:给出n和m.求sum(i^m)%2^32.(1<=i<=n) (1<=n<=10^15,0<=m<=50). 思路:本题有两种方法:二分和矩阵. (1)二分:设我们用DFS(n,m)来计算上面的式子.假如n为奇数,比如n=13,那么我们单独计算13^m,那么剩下的是n=12.前一半是DFS(6,m),后一半是7^m+8^m+……12^m. 进而n…

题目链接:https://vjudge.net/problem/LightOJ-1132 题目意思:(1K + 2K + 3K + ... + NK) % 232 矩阵快速幂的题目一般都很短,这道题也一样就是这么简单. 思路:运用到了组合数a^k=C(k,0)*a^k+C(k,1)*a^(k-1)+C(k,2)*a^(k-2)+C(k,3)*a^(k-3)+C(k,4)*a^(k-4)+……C(k,k)*a^(k-k),运用这个式子我们可以构造以下矩阵. C(k,), C(k,), C(k,),…

题目链接:http://lightoj.com/volume_showproblem.php?problem=1132 题意: 给定n.k,求(1K + 2K + 3K + ... + NK) % 232. 题解: 设sum(i) = 1K + 2K + 3K + ... + iK 所以要从sum(1)一直推到sum(n). 所以要找出sum(i)和sum(i+1)之间的关系: 好了可以造矩阵了. (n = 6时) 矩阵表示(大小为 1 * (k+2)): 初始矩阵start: 也就是: 特殊矩…

题目大意:求(1^K + 2^K + 3K + - + N^K) % 2^32 解题思路: 借用别人的图 能够先打表,求出Cnm,用杨辉三角能够高速得到 #include<cstdio> typedef unsigned long long ll; const int N = 55; const ll mod = (1LL << 32); struct Matrix{ ll mat[N][N]; }A, B, tmp; ll n, num[N]; ll C[N][N]; int K…

题目链接: http://poj.org/problem?id=1707 Language: Default Sum of powers Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 735   Accepted: 354 Description A young schoolboy would like to calculate the sum   for some fixed natural k and differe…

题目链接:Path Sum II | LeetCode OJ Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum. For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1 return [ [5,4,11,2],…

题目链接:Populating Next Right Pointers in Each Node II | LeetCode OJ Follow up for problem "Populating Next Right Pointers in Each Node". What if the given tree could be any binary tree? Would your previous solution still work? Note: You may only u…

原文标题:Functional Android (II): Collection operations in Kotlin 原文链接:http://antonioleiva.com/collection-operations-kotlin/ 原文作者:Antonio Leiva(http://antonioleiva.com/about/) 原文发布:2015-09-29 在简化代码方面,Lambda表达式是一个杰出的工具,而且还可以完成之前不可能完成的事.我们在这个系列文章的第一篇(Unlea…

统计分析中Type I Error与Type II Error的区别 在统计分析中,经常提到Type I Error和Type II Error.他们的基本概念是什么?有什么区别? 下面的表格显示 between truth/falseness of the null hypothesis and outcomes of the test " -------|-------|------- | Judgement of Null Hypothesis H0 | Valid | Invalid |…