clean up Contest package

Author: fishercoder1534

Contest/src/_20160910_4th_contest/IntegerReplacement.java renamed to EASY/src/easy/IntegerReplacement.java

@@ -1,41 +1,8 @@
-package _20160910_4th_contest;
+package easy;
 
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.LinkedList;
-import java.util.Queue;
-import java.util.Set;
+import java.util.*;
 
 public class IntegerReplacement {
-    public static int integerReplacement_failed(int n) {
-        if(n == 1) return 0;
-        int steps = 0;
-        while(n != 1){
-            if(n%2 == 1 && n > 1) {
-                n -= 1;
-                steps++;
-            }
-            
-            n /= 2;
-            steps++;
-        }
-        return steps;
-    }
-    
-    public static int integerReplacement_failed_2(int n) {
-        if(n == 1) return 0;
-        int temp = 2, steps = 1;
-        while(temp <= n){
-            temp *= 2;
-            steps++;
-            
-            if(temp%2 == 1){
-                temp += 1;
-                steps++;
-            }
-        }
-        return steps;
-    }
 
     public static int integerReplacement(int n) {
         long min = Long.MAX_VALUE;

Contest/src/_20160910_4th_contest/RotateFunction.java renamed to EASY/src/easy/RotateFunction.java

@@ -1,4 +1,4 @@
-package _20160910_4th_contest;
+package easy;
 
 //F(k) = 0 * Bk[0] + 1 * Bk[1] + ... + (n-1) * Bk[n-1]
 public class RotateFunction {

Contest/src/_20160910_4th_contest/RandomPickIndex.java renamed to MEDIUM/RandomPickIndex.java

@@ -9,7 +9,10 @@ public class RandomPickIndex {
 
 }
 
+//TODO: use reservoir sampling to solve it again
+
 class Solution {
+    //brute force
     int[] input;
     java.util.Random rand = new java.util.Random();
     public Solution(int[] nums) {
@@ -30,7 +33,7 @@ public int pick(int target) {
 }
 
 
-class Solution_MLE {
+class Solution_MemoryLimitExceeded {
 
     private Map<Integer, List<Integer>> map = new HashMap();
     java.util.Random rand = new java.util.Random();

README.md

@@ -2,6 +2,9 @@
 |  #  |      Title     |   Solutions   | Time          | Space         | Difficulty  | Tag          | Notes
 |-----|----------------|---------------|---------------|---------------|-------------|--------------|-----
 |415|[Add Strings](https://leetcode.com/problems/add-strings/)|[Solution](../../blob/master/EASY/src/easy/AddStrings.java)| O(n)|O(1) | Easy|
+|398|[Random Pick Index](https://leetcode.com/problems/random-pick-index/)|[Solution](../../blob/master/MEDIUM/src/medium/RandomPickIndex.java)| | | Medium| Reservoir Sampling
+|397|[Integer Replacement](https://leetcode.com/problems/integer-replacement/)|[Solution](../../blob/master/EASY/src/easy/IntegerReplacement.java)| ? | ? | Easy| BFS
+|396|[Rotate Function](https://leetcode.com/problems/rotate-function/)|[Solution](../../blob/master/EASY/src/easy/RotateFunction.java)| O(n^2) could be optimized to O(n) | O(1) | Easy|
 |390|[Elimination Game](https://leetcode.com/problems/elimination-game/)|[Solution](../../blob/master/MEDIUM/src/medium/EliminationGame.java)| O(logn)|O(1) | Medium|
 |389|[Find the Difference](https://leetcode.com/problems/find-the-difference/)|[Solution](../../blob/master/EASY/src/easy/FindTheDifference.java)| O(n)|O(1) | Easy|
 |388|[Longest Absolute File Path](https://leetcode.com/problems/longest-absolute-file-path/)|[Solution](../../blob/master/MEDIUM/src/medium/LongestAbsoluteFilePath.java)| O(n)|O(d) | Medium| Stack