首页 > 代码库 > 【LeetCode】3Sum Closest

【LeetCode】3Sum Closest

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

    For example, given array S = {-1 2 1 -4}, and target = 1.

    The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).
public class Solution {
    public int threeSumClosest(int[] num, int target) {
        if(num.length<=2)
            return 0;
        Arrays.sort(num);
        int re=0;
        int min = Integer.MAX_VALUE;
        for(int i=0;i<num.length-2;i++){
            int temp = num[i];
            int start = i+1;
            int end=num.length-1;
            while(end>start){
                int sr = num[start]+num[end]+temp;
                if(sr==target)
                    return target;
                if(sr>target){
                    if(Math.abs(sr-target)<min){
                        min=Math.abs(sr-target);
                        re=sr;
                    }
                        
                    end--;
                    continue;
                }
                if(sr<target){
                    if(Math.abs(sr-target)<min){
                        min=Math.abs(sr-target);
                        re=sr;
                    }
                        
                    start++;
                    continue;
                }
            }
        }
        return re;
        
    }
}