The cows don't use actual bowling balls when they go bowling. They each take a number (in the range 0..99), though, and line up in a standard bowling-pin-like triangle like this: 7 3 8 8 1 0 2 7 4 4 4 5 2 6 5 Then the other cows traverse the triangle…

一道经典Dp. 定义dp[i][j] 表示由i个节点,j 层高度的累计方法数 状态转移方程为: 用i个点组成深度最多为j的二叉树的方法树等于组成左子树的方法数 乘于组成右子树的方法数再累计. & / \ @ # / \ @ @ 如图中 & 为顶点, @ 为左子树, # 为右子树 需要注意的是,左子树的节点数目同样也为奇数 然后遍历一遍从k = 1 到 i - 2, 考虑上一层所有的左/右子树方法数再作累加 最后输出答案的时候减去上一层累加数即可 /* ID: wushuai2 PROG:…

Kattis - honey[DP] 题意 有一只蜜蜂,在它的蜂房当中,蜂房是正六边形的,然后它要出去,但是它只能走N步,第N步的时候要回到起点,给出N, 求方案总数 思路 用DP 因为N == 14 所以 最多走7步 我们不妨设 (7, 7) 为原点,然后 dp[0][7][7] = 1 因为 N == 0 的时候 方案数只有一个 那就是 不动吧.. dp[i][j][k] i 代表第几步 j k 分别表示 目前的位置 一个点 在一张图里面本来有八个方向可以走 这里六边形 我们只取六个方向就可…

HDOJ 1423 Greatest Common Increasing Subsequence [DP][最长公共上升子序列] Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 8768 Accepted Submission(s): 2831 Problem Description This is a problem from ZOJ 24…

HDOJ 1501 Zipper [DP][DFS+剪枝] Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 10886 Accepted Submission(s): 3925 Problem Description Given three strings, you are to determine whether the third str…

HDOJ 1257 最少拦截系统 [DP] Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 50753 Accepted Submission(s): 19895 Problem Description 某国为了防御敌国的导弹袭击,发展出一种导弹拦截系统.但是这种导弹拦截系统有一个缺陷:虽然它的第一发炮弹能够到达任意的高度,但是以后每一发炮弹…

HDOJ 1159 Common Subsequence[DP] Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 44280 Accepted Submission(s): 20431 Problem Description A subsequence of a given sequence is the given sequence wit…

HDOJ_1087_Super Jumping! Jumping! Jumping! [DP] Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 44670 Accepted Submission(s): 20693 Problem Description Nowadays, a kind of chess game called "Super…

POJ_2533 Longest Ordered Subsequence[DP][最长递增子序列] Longest Ordered Subsequence Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 58448 Accepted: 26207 Description A numeric sequence of ai is ordered if a1 < a2 < - < aN. Let the subsequenc…

HackerRank - common-child[DP] 题意 给出两串长度相等的字符串,找出他们的最长公共子序列e 思路 字符串版的LCS AC代码 #include <iostream> #include <cstdio> #include <algorithm> #include <cmath> #include <deque> #include <vector> #include <queue> #include…