LeetCode_3Sum Closest

 1 class Solution {
 2 public:
 3     int threeSumClosest(vector<int> &num, int target) {
 4         // Start typing your C/C++ solution below
 5         // DO NOT write int main() function
 6         sort(num.begin(), num.end());
 7         int minSum = num[0] + num[1] + num[2];
 8         int minDiff = abs(minSum - target) ;
 9         
10         for(int i =0; i< num.size() -2 ;i++){
11             int startS = i + 1 ;
12             int endS = num.size() - 1 ;
13             while(startS < endS){
14              
15              int sum = num[i] + num[startS] + num[endS];
16              int diff = abs(sum - target);
17              
18              if(diff < minDiff){
19                  minDiff = diff;
20                  minSum = sum;
21              }
22              if(sum == target) return target;
23              if(sum < target)
24                          startS ++;
25              else
26                          endS --;
27             
28             }
29         }
30         
31         return minSum;
32     }
33 };
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