Leetcode 16

Python Solution

Author: kyle8998

Diff for: README.md

@@ -19,6 +19,7 @@ Personal Practice Set - Doing One a Day (sometimes) in a Variety of Languages!!
 | 13 | Easy       | [Roman to Integer](leetcode/13-Easy-Roman-To-Integer/problem.md)                             | [C](leetcode/13-Easy-Roman-To-Integer/answer.c)                  |
 | 14 | Easy       | [Longest Common Prefix](leetcode/14-Easy-Longest-Common-Prefix/problem.md)                   | [Python](leetcode/14-Easy-Longest-Common-Prefix/answer.py)       |
 | 15 | Medium     | [3Sum](leetcode/15-Medium-3Sum/problem.md)                                                   | [Python](leetcode/15-Medium-3Sum/answer.py)                      |
+| 16 | Medium     | [3Sum Closest](leetcode/16-Medium-3Sum-Closest/problem.md)                                   | [Python](leetcode/16-Medium-3Sum-Closest/answer.py)              |
 | 20 | Easy       | [Valid Parentheses](leetcode/20-Easy-Valid-Parentheses/problem.md)                           | [Java](leetcode/20-Easy-Valid-Parentheses/answer.java)           |
 | 21 | Easy       | [Merge Two Sorted Lists](leetcode/21-Easy-Merge-Two-Sorted-Lists/problem.md)                 | [Java](leetcode/21-Easy-Merge-Two-Sorted-Lists/answer.java)      |
 | 22 | Medium     | [Generate Parentheses](leetcode/22-Medium-Generate-Parentheses/problem.md)                   | [Python](leetcode/22-Medium-Generate-Parentheses/answer.py)      |

Diff for: leetcode/16-Medium-3Sum-Closest/answer.py

@@ -0,0 +1,42 @@
+#!/usr/bin/python
+
+#------------------------------------------------------------------------------
+
+class Solution:
+    def threeSumClosest(self, nums, target):
+        """
+        :type nums: List[int]
+        :type target: int
+        :rtype: int
+        """
+        
+        nums.sort()
+        
+        result = float('inf')
+        
+        # Loop through each index, then use two pointers to close in the rest of the array
+        for i in range(len(nums)-2):
+            l, r = i+1, len(nums)-1
+            
+            while l < r:
+                # Current sum of the three elements
+                curr_sum = nums[i] + nums[l] + nums[r]
+                # If the difference is smaller, make it the result
+                if abs(target - curr_sum) < abs(target - result):
+                    result = curr_sum
+                    
+                if curr_sum == target:
+                    return curr_sum
+                elif curr_sum < target:
+                    l += 1
+                else:
+                    r -= 1
+                    
+        return result
+
+#------------------------------------------------------------------------------
+#Testing
+
+
+
+main()

Diff for: leetcode/16-Medium-3Sum-Closest/problem.md

@@ -0,0 +1,18 @@
+# Problem 16: 3Sum Closest
+
+
+#### Difficulty: Medium
+
+#### Problem
+
+Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly one solution.
+
+#### Example
+
+<pre>
+
+For example, given array S = {-1 2 1 -4}, and target = 1.
+
+The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).
+
+</pre>