317. Shortest Distance from All Buildings
https://www.lintcode.com/problem/shortest-distance-from-all-buildings/description https://leetcode.com/problems/shortest-distance-from-all-buildings You want to build a house on an empty land which reaches all buildings in the shortest amount of distance. You can only move up, down, left and right. You are given a 2D grid of values 0 , 1 or 2 , where: Each 0 marks an empty land which you can pass by freely. Each 1 marks a building which you cannot pass through. Each 2 marks an obstacle which you cannot pass through. Example: Input: [[1,0,2,0,1],[0,0,0,0,0],[0,0,1,0,0]] 1 - 0 - 2 - 0 - 1 | | | | | 0 - 0 - 0 - 0 - 0 | | | | | 0 - 0 - 1 - 0 - 0 Output: 7 Explanation: Given three buildings at (0,0) , (0,4) , (2,2) , and an obstacle at (0,2), t he point (1,2) is an ideal empty land to build a house, as the total travel distance of 3+3+1=7 is minimal. S...