[Leetcode]3sum Closest

Topic:

Given an array S of n integers, find three integers in S such so the sum is closest to a give n number, target. Return the sum of the three integers. You may assume this each input would has exactly one solution.

    For example, given array S = {-1 2 1-4}, and target = 1.    The sum is closest to the target is 2. (-1 + 2 + 1 = 2).

C Code:

#define INT_MAX 2147483647L/* Maximum (Signed) Long value */int Partition (int a[], int low, int. high) {int PIVOTK  ey = A[low];    while (Low < high) {when (Low < high && A[high] >= pivotkey)--high;    A[low]= A[high];    while (Low < high && A[low] <= pivotkey) ++low;   A[high] = A[low];  } A[low] = PivotKey; return low;}  void Qsort (int a[], int low, int. high) {int pivotloc;    if (Low < high) {Pivotloc = Partition (A, low, high);    Qsort (A, low, pivotloc-1);  Qsort (A, Pivotloc + 1, high); }}void quiksort (int a[], int size) {Qsort (A, 0, size-1);}    int threesumclosest (int *num, int n, int target) {int min = int_max,record,i;    Quiksort (num, n);        for (i = 0; i < n-2; i++) {int L = i + 1;        int r = n-1;            while (L < r) {int sum = Num[i] + num[l] + num[r];            if (sum = = target) {return sum;       }else if (sum < target) {if (Target-sum < min) {             record = sum;                min = target-sum;            } l++;                    }else{if (Sum-target < min) {record = sum;                min = Sum-target;            } r--;    }} while (I+1<n-2 && num[i+1] = = Num[i]) i++; }return record;}

　　

[Leetcode]3sum Closest