LeetCode_3Sum Closest

class Solution {
public:
int threeSumClosest(vector<int> &num, int target) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
sort(num.begin(), num.end());
int minSum = num[0] + num[1] + num[2];
int minDiff = abs(minSum - target) ;

for(int i =0; i< num.size() -2 ;i++){
int startS = i + 1 ;
int endS = num.size() - 1 ;
while(startS < endS){

int sum = num[i] + num[startS] + num[endS];
int diff = abs(sum - target);

if(diff < minDiff){
minDiff = diff;
minSum = sum;
}
if(sum == target) return target;
if(sum < target)
startS ++;
else
endS --;

}
}

return minSum;
}
};