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 right at any point in time. The robot is trying to reach the bottom-right corner of the grid (marked ‘Finish’ in the diagram below). Now consider if some obstacles are added to the grids. How many unique paths would there be? An obstacle and empty space is marked as 1 and 0 respectively in the grid.
Given n non-negative integers representing the histogram’s bar height where the width of each bar is 1, find the area of largest rectangle in the histogram. Above is a histogram where width of each bar is 1, given height = [2,1,5,6,2,3]. The largest rectangle is shown in the shaded area, which has area = 10 unit. Example: Input: [2,1,5,6,2,3] Output: 10 Solution: Push height into the stack in ascending order. When we encounter a height that is shorter than te top of the stack, we start to calculate area by popping heights out of the stack.
Given a 2D binary matrix filled with 0’s and 1’s, find the largest rectangle containing only 1’s and return its area. Example: Input: [ ["1","0","1","0","0"], ["1","0","1","1","1"], ["1","1","1","1","1"], ["1","0","0","1","0"] ] Output: 6 Hint Height: 1 0 1 0 0 2 0 2 1 1 3 1 3 2 2 4 0 0 3 0 Left: 0 0 2 0 0 0 0 2 2 2 0 0 2 2 2 0 0 0 3 0 Right:
A group of two or more people wants to meet and minimize the total travel distance. You are given a 2D grid of values 0 or 1, where each 1 marks the home of someone in the group. The distance is calculated using Manhattan Distance, where distance(p1, p2) = |p2.x - p1.x| + |p2.y - p1.y|. Example: Input: 1 - 0 - 0 - 0 - 1 | | | | | 0 - 0 - 0 - 0 - 0 | | | | | 0 - 0 - 1 - 0 - 0 Output: 6 ###Explanation: Given three people living at (0,0), (0,4), and (2,2): The point (0,2) is an ideal meeting point, as the total travel distance of 2+2+2=6 is minimal.
The longest common subsequence (LCS) problem is the problem of finding the longest subsequence common to all sequences in a set of sequences (often just two sequences). It differs from the longest common substring problem: unlike substrings, subsequences are not required to occupy consecutive positions within the original sequences. Optimal Substructure: Let the input sequences be X[0..m-1] and Y[0..n-1] of lengths m and n respectively. And let L(X[0..m-1], Y[0..n-1]) be the length of LCS of the two sequences X and Y.
Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node. Note: A leaf is a node with no children. Example: Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 return its minimum depth = 2. Solution: Recursion /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ class Solution { public int minDepth(TreeNode root) { if (root == null) return 0; int left = minDepth(root.
Given n non-negative integers a1, a2, …, an , where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of line i is at (i, ai) and (i, 0). Find two lines, which together with x-axis forms a container, such that the container contains the most water. Note You may not slant the container and n is at least 2. The above vertical lines are represented by array [1,8,6,2,5,4,8,3,7].
Install manually Step 1: Download the source package from the oracle repository. If your computer is 64-bit, download the x64 version; if it is 32-bit, download the x86 version. Step 2: Extract from the compressed file and move the package folder to /usr/java. rememeber to run these commands as sudo is not the root user. mv downloads-folder/jdk-<version>-linux-xxx.tar.gz /usr/java tar -xvzf jdk-<version>-linux-xxx.tar.gz rm jdk-<version>-linux-xxx.tar.gz Step 3: Add the java path to the ~/.
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 right at any point in time. The robot is trying to reach the bottom-right corner of the grid (marked ‘Finish’ in the diagram below). How many possible unique paths are there? Above is a 7 x 3 grid. How many possible unique paths are there?