Leetcode 3Sum Closest (C,c++,java,python)

Problem:

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).

Solution: This question and 15 basic similar, even more simple, only need to compare and the result can, encounter and equal to target when you directly return it!!!
To give an array of integers, find the one with the shortest distance of three numbers and the value with the given target.
Problem-solving ideas: Look directly at the code, not read my 15 questions
Java source code (spents 342ms):

public class Solution {public    int threesumclosest (int[] nums, int target) {        int length=nums.length,min= Integer.max_value;        Arrays.sort (nums);        for (int i=0;i<length-2;i++) {            if (i>0 && nums[i]==nums[i-1]) continue;            int begin=i+1,end=length-1;            while (begin<end) {                int sum=nums[i]+nums[begin]+nums[end];                if (Math.Abs (sum-target) <math.abs (Min)) Min=sum-target;                if (sum==target) return target;                else if (sum>target) end--;                else begin++;            }        }        return min+target;}    }

C Language Source code (spents 9ms):

int abs (int tar) {return tar>0?tar:-tar;}    void QuickSort (int* nums,int first,int end) {int l=first,r=end;    if (first>=end) return;    int temp=nums[l];        while (L<r) {while (L<r && nums[r]>=temp) r--;        if (l<r) nums[l]=nums[r];        while (L<r && nums[l]<=temp) l++;    if (l<r) nums[r]=nums[l];    } nums[l]=temp;    QuickSort (NUMS,FIRST,L-1); QuickSort (nums,l+1,end);}    int Threesumclosest (int* nums, int numssize, int target) {int begin,end,i,sum,min=int_max;    QuickSort (nums,0,numssize-1);        for (i=0;i<numssize-2;i++) {if (i>0 && nums[i]==nums[i-1]) continue;        begin=i+1;end=numssize-1;            while (Begin<end) {sum=nums[i]+nums[begin]+nums[end];            if (ABS (Sum-target) <abs (Min)) Min=sum-target;            if (sum==target) return target;            else if (sum>target) end--;        else begin++; }} return min+target;}

C + + source code (spents 12ms):

Class Solution {Public:int threesumclosest (vector<int>& nums, int target) {int length=nums.size (), Mi        n=2147483647;        QuickSort (nums,0,length-1);            for (int i=0;i<length-2;i++) {if (i>0 && nums[i]==nums[i-1]) continue;            int begin=i+1,end=length-1;                while (begin<end) {int sum=nums[i]+nums[begin]+nums[end];                if (ABS (Sum-target) <abs (Min)) Min=sum-target;                if (sum==target) return target;                else if (sum>target) end--;            else begin++;    }} return min+target;    }private:int ABS (int t) {return t>0?t:-t;        } void QuickSort (vector<int>& nums,int first,int end) {int l=first,r=end,tmp;        if (first>=end) return;        TMP=NUMS[L];            while (L<r) {while (L<r && nums[r]>=tmp) r--;            if (l<r) nums[l]=nums[r]; while (L<r && nums[l]<=tMP) l++;        if (l<r) nums[r]=nums[l];        } nums[l]=tmp;        QuickSort (NUMS,FIRST,L-1);    QuickSort (Nums,l+1,end); }};

Python source code (spents 127ms):

Class solution:    # @param {integer[]} nums    # @param {integer} target    # @return {integer}    def Threesumclosest (self, Nums, target):        Length=len (nums); min=2147483647        Nums.sort () for        I in range (length-2):            if i>0 and nums[i]==nums[i-1]:continue            begin =i+1;end=length-1 while            begin<end:                sum=nums[i]+nums[begin]+nums[end]                if ABS (Sum-target) <abs ( Min): Min=sum-target                if Sum==target:return target                elif sum>target:end-=1                else:begin+=1        Return Min+target

Leetcode 3Sum Closest (C,c++,java,python)