LeetCode——628. 三个数的最大乘积（C++）

链接：https://leetcode-cn.com/problems/maximum-product-of-three-numbers

给定一个整型数组，在数组中找出由三个数组成的最大乘积，并输出这个乘积。

示例 1:

输入: [1,2,3]
输出: 6

示例 2:

输入: [1,2,3,4]
输出: 24

我参考了大神的思路寻找到的最优解，这里仅做记录：

#include
#include
#include
using namespace std;

class Solution {
public:
    int maximumProduct(vector& nums) {

        int len = nums.size();
        int res;
        // 长度=3 直接乘 
        if(len == 3){
            return nums[len - 1] * nums[len - 2] * nums[len - 3];
        }
        // 如果最后面是两个负数，就要比较乘积大小，如果不是两个负数，那就直接返回后3个数乘积 
        // 排序（这里的排序可做优化，寻找到最大的三个数，和最小的两个数即可）
//        sort(nums.begin(), nums.end());
          int min1 = INT_MAX, min2 = INT_MAX, max1 = INT_MIN, max2 = INT_MIN, max3 = INT_MIN;
          for(int i = 0; i < nums.size(); i++){
              int a = nums[i];
              int temp = 0;
              if(a <= min1){
                  min2 = min1;
                  min1 = a;
              }
              else if(a < min2){
                  min2 = a;
              }
              if(a >= max1){
                  max3 = max2;
                  max2 = max1;
                  max1 = a;
              }else if(a >= max2){
                  max3 = max2;
                  max2 = a;
              }else if(a > max3){
                  max3 = a;
              }
//              cout< v{6,2,6,5,1,2};
    
//    vector v{-4,-3,-2,-1,60};

//    vector v {722,634,-504,-379,163,-613,-842,-578,750,951,-158,30,-238,-392,-487,-797,-157,-374,999,-5,
//    -521,-879,-858,382,626,803,-347,903,-205,57,-342,186,-736,17,83,726,-960,343,-984,937,-758,-122,577,-595,-544,
//    -559,903,-183,192,825,368,-674,57,-959,884,29,-681,-339,582,969,-95,-455,-275,205,-548,79,258,35,233,203,20,
//    -936,878,-868,-458,-882,867,-664,-892,-687,322,844,-745,447,-909,-586,69,-88,88,445,-553,-666,130,-640,-918,-7,-420,-368,250,-786}; // 943695360 
    Solution sol;
    cout<