BestMeetingPoint296

Author: fluency03

README.md

@@ -55,11 +55,11 @@
 | [Graph](https://github.com/fluency03/leetcode-java/blob/master/src/graph) |
 
 
-# Total: 537
+# Total: 538
 
 |   Easy  |  Medium | Hard |  -  |
 |:-------:|:-------:|:----:|:---:|
-|   142   |   292   |  91  | 12  |
+|   142   |   292   |  92  | 12  |
 
 
 | Question | Solution | Difficulty |
@@ -301,6 +301,7 @@
 | [291. Word Pattern II](https://leetcode.com/problems/word-pattern-ii/) | [Solution](https://github.com/fluency03/leetcode-java/blob/master/src/WordPatternII291.java) | Hard |
 | [293. Flip Game](https://leetcode.com/problems/flip-game/) | [Solution](https://github.com/fluency03/leetcode-java/blob/master/src/FlipGame293.java) | Easy |
 | [295. Find Median from Data Stream](https://leetcode.com/problems/find-median-from-data-stream/) | [Solution](https://github.com/fluency03/leetcode-java/blob/master/src/FindMedianFromDataStream295.java) | Hard |
+| [296. Best Meeting Point](https://leetcode.com/problems/best-meeting-point/) | [Solution](https://github.com/fluency03/leetcode-java/blob/master/src/BestMeetingPoint296.java) | Hard |
 | [297. Serialize and Deserialize Binary Tree](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/) | [Solution](https://github.com/fluency03/leetcode-java/blob/master/src/SerializeAndDeserializeBinaryTree297.java) | Hard |
 | [298. Binary Tree Longest Consecutive Sequence](https://leetcode.com/problems/binary-tree-longest-consecutive-sequence/) | [Solution](https://github.com/fluency03/leetcode-java/blob/master/src/BinaryTreeLongestConsecutiveSequence298.java) | Medium |
 | [299. Bulls and Cows](https://leetcode.com/problems/bulls-and-cows/) | [Solution](https://github.com/fluency03/leetcode-java/blob/master/src/BullsAndCows299.java) | Medium |

src/BestMeetingPoint296.java

@@ -0,0 +1,55 @@
+/**
+ * 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 (http://en.wikipedia.org/wiki/Taxicab_geometry), 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. So return 6.
+ */
+
+public class BestMeetingPoint296 {
+    /**
+     * https://leetcode.com/problems/best-meeting-point/discuss/74186/14ms-java-solution
+     */
+    public int minTotalDistance(int[][] grid) {
+        int m = grid.length;
+        int n = grid[0].length;
+        List<Integer> I = new ArrayList<>(m);
+        List<Integer> J = new ArrayList<>(n);
+        for(int i = 0; i < m; i++){
+            for(int j = 0; j < n; j++){
+                if(grid[i][j] == 1){
+                    I.add(i);
+                    J.add(j);
+                }
+            }
+        }
+        return getMin(I) + getMin(J);
+    }
+
+    private int getMin(List<Integer> list){
+        int ret = 0;
+        Collections.sort(list);
+        int i = 0;
+        int j = list.size() - 1;
+        while(i < j){
+            ret += list.get(j--) - list.get(i++);
+        }
+        return ret;
+    }
+
+}