leetcode628

这道题十分不容易啊，做到半夜。

class Solution {
public:
    static int cmp628(int a, int b)
    {
        return a > b;
    }

    static int cmp628_2(int a, int b)
    {
        return abs(a) < abs(b);
    }

    int maximumProduct(vector<int>& nums) {
        const int N = 10000;
        int Pos[N];
        int Nag[N];
        int Nor[N];

        int i = 0, j = 0, k = 0;
        for (auto n : nums)
        {
            if (n >= 0)
            {
                Pos[i] = n;
                i++;
            }
            else
            {
                Nag[j] = n;
                j++;
            }
            Nor[k] = n;
            k++;
        }

        sort(Pos, Pos + i, cmp628);
        sort(Nag, Nag + j);
        sort(Nor, Nor + k, cmp628_2);

        int a = INT_MIN, b = INT_MIN, c = INT_MIN, d = INT_MIN, max = INT_MIN;

        //三正
        if (i >= 3)
        {
            a = Pos[0] * Pos[1] * Pos[2];
            if (j >= 2)
            {
                b = Pos[0] * Nag[0] * Nag[1];
            }
        }
        else if (i >= 2)
        {
            a = Pos[0] * Pos[1] * Nag[0];
            if (j >= 2)
            {
                b = Pos[0] * Nag[0] * Nag[1];
            }
        }
        if (j >= 3)
        {
            c = Nag[0] * Nag[1] * Nag[2];
            if (i >= 2)
            {
                d = Nag[j - 1] * Pos[0] * Pos[1];
            }
            else if (i == 1)
            {
                d = Nag[0] * Nag[1] * Pos[0];
            }

        }
        else if (j >= 2)
        {
            c = Nag[0] * Nag[1] * Pos[0];
            if (i >= 2)
            {
                d = Nag[j - 1] * Pos[0] * Pos[1];
            }
            else if (i == 1)
            {
                d = Nag[0] * Nag[1] * Pos[0];
            }
        }

        if (max < a)
            max = a;
        if (max < b)
            max = b;
        if (max < c)
            max = c;
        if (max < d)
            max = d;

        return max;
    }
};