Frontier_Setter的博客

http://train.usaco.org/usacoprob2?a=qNexyVCSx2z&S=twofive题目大意：给一个5*5的字符方阵（A-Z），阅读顺序为从上到下逐行从左到右念下来，要求每一个位置的字母比它上方与左侧的字母要大。题目有两个要求：1、给一个方阵求它在所有可能的方阵中排第几个（按字典序升序排列）2、给序号，求出方阵1、要枚举的话有25！种情况，肯定不是这么搞的2、...

https://leetcode.com/problems/longest-palindromic-subsequence/Given a string s, find the longest palindromic subsequence's length in s. You may assume that the maximum length of s is 1000.Example...

https://leetcode.com/problems/target-sum/You are given a list of non-negative integers, a1, a2, ..., an, and a target, S. Now you have 2 symbols+and-. For each integer, you should choose one fro...

https://leetcode.com/problems/partition-equal-subset-sum/Given anon-emptyarray containingonly positive integers, find if the array can be partitioned into two subsets such that the sum of elemen...

We are playing the Guess Game. The game is as follows:I pick a number from1ton. You have to guess which number I picked.Every time you guess wrong, I'll tell you whether the number I picked is...

https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-cooldown/Say you have an array for which theithelement is the price of a given stock on dayi.Design an algorithm to find the ...

https://leetcode.com/problems/unique-paths-ii/submissions/A robot is located at the top-left corner of a m x n grid (marked 'Start' in the diagram below).The robot can only move either down or ri...

https://leetcode.com/problems/triangle/Given a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below.For example, given the following...

https://leetcode.com/problems/decode-ways/A message containing letters from A-Z is being encoded to numbers using the following mapping:'A' -> 1'B' -> 2...'Z' -> 26Given a non-emp...

https://leetcode.com/problems/coin-change/You are given coins of different denominations and a total amount of money amount. Write a function to compute the fewest number of coins that you need to ...

https://leetcode.com/problems/perfect-squares/Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, ...) which sum to n.Example 1:Input: n = 12...

https://leetcode.com/problems/maximum-product-subarray/Given an integer array nums, find the contiguous subarray within an array (containing at least one number) which has the largest product.Exa...

https://leetcode.com/problems/word-break/Given a non-empty string s and a dictionary wordDict containing a list of non-emptywords, determine if s can be segmented into a space-separated sequence of...

http://train.usaco.org/usacoprob2?a=iHzQON4VeJX&S=vans题目大意：由4条横线，N条纵线划划分的网络，要求一条路线经过每个网点一次且仅一次，求共有多少条这样的路径想法一：枚举，不可能，其实到第五章之后的题目好像都不太能枚举了想法二：相当于先有一个最外层的大矩形轮廓，然后逐步“下凹”，只要下凹的那一格在当前外表面轮廓组成中只有一条边就不会使最...

https://leetcode.com/problems/knight-probability-in-chessboard/On anNxNchessboard, a knight starts at ther-th row andc-th column and attempts to make exactlyKmoves. The rows and columns are 0...