Yuwen's Hero

问题： F0 = 0 F1 = 1 Fn = Fn − 1 + Fn − 2 求Fn Fibonacci数列是一个非常经典的用递归解决的问题。递归方法如下： public int F(int n) { if (n == 0) return 0; else if (n == 1) return 1; else return F(n - 1) + F(n - 2)

Given a matrix with 1s and 0s, please find the number of groups of 1s. A group is defined by horizontally or vertically adjacent 1s. For example, there are four groups of 1s in figure below. Anal

If you want to know what Boggle is, please wiki or google it. Or refer to http://goo.gl/GythQ  In this implementation, we need to use a dictionary. Go to http://goo.gl/vaq4Z to download it and as it

Given an image represented by a matrix, write a method to rotate the image by 90 degrees. Can you do this in place? static void rotateClockwise(int[][] matrix) { int length = matrix.length - 1; for

给你一个n * n 的二维char数组 内部存的是 'X' 和 'O'，形式如下 X  X  X  X  X X  O  O  O  X X  X  O  O  X X  X  X  O  X X  O  X  X  X 编写一个函数将被'X'包围的'O'统统变成'X'。 比如下标为 (1,1) (1,2) (1,3) (2,2) (2,3) (3,3)的'O'需要被变成'X'，而下标

Given a 2D board and a word, find if the word exists in the grid. The word can be constructed from letters of sequentially adjacent cell, where "adjacent" cells are those horizontally or vertically

Given a 2D binary matrix filled with 0's and 1's, find the largest rectangle containing all ones and return its area. public class Solution { public int maximalRectangle(char[][] matrix) {

Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties: Integers in each row are sorted from left to right. The first integer o

Given a m x n matrix, if an element is 0, set its entire row and column to 0. Do it in place. public class Solution { public void setZeroes(int[][] matrix) { int[] row = new int[matri

Question: Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path. Note: You can only move either d

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 triangle [ [2], [3,4], [

Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order. For example, Given n = 3, You should return the following matrix: [ [ 1, 2, 3 ], [ 8, 9, 4 ],

问题： 给定一个矩阵，从外向内顺时针打印矩阵中的每一个数字。 例如：给定矩阵： 1    2    3    4 5    6    7    8 9    10   11  12 13   14   15  16 输出应该为：{1,2,3,4,8,12,16,15,14,13,9,5,6,7,11,10} 分析： 问题的本质其实就是打印一

前言： 今天花了很长时间，看了无数人写的帖子，但是几乎没有人把这个问题一下子说得很清楚，所以，我把这个问题按照自己的思路写出来，希望能够把这个问题讲清楚。 问题： 求一个M*N的矩阵的最大子矩阵和。 比如在如下这个矩阵中：  0 -2 -7  0  9  2 -6  2 -4  1 -4  1 -1  8  0 -2  拥有最大和的子矩阵为：  9 2 -4 1 -1 8

Given an integer matrix, find the length of the longest increasing path. From each cell, you can either move to four directions: left, right, up or down. You may NOT move diagonally or move outside