16. 3Sum Closest

# 12：21 --> 
class Solution(object):
    def threeSumClosest(self, num, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: int
        """
        num.sort()
        result = num[0] + num[1] + num[2]
        for i in range(len(num) - 2):
            j, k = i+1, len(num) - 1
            while j < k:
                sum = num[i] + num[j] + num[k]
                if sum == target:
                    return sum
                
                if abs(sum - target) < abs(result - target):
                    result = sum
                
                if sum < target:
                    j += 1
                elif sum > target:
                    k -= 1
            
        return result
        # nums.sort()
        # diff = 1000000
        # for i in xrange(len(nums) - 2):
        #     start, end  = i + 1, len(nums) - 1
        #     sums = nums[start] + nums[end] + nums[i]
        #     while start + 1 < end:
        #         sums = nums[start] + nums[end] + nums[i]
        #         if sums == target:
        #             return target
        #         elif sums > target:
        #             end -= 1
        #         else:
        #             start += 1
        #     newnums = nums[start] + nums[end] + nums[i]
        #     if abs (target - sums) < diff:
        #         diff = abs (target - sums)
        #         result = sums
        #     if abs (target - newnums) < diff:
        #         diff = abs (target - newnums)
        #         result = newnums
        #     # print diff, result, nums[i], nums[start], nums[end]
        # return result