求数组乘集最大结果

Given an integer array nums, find the contiguous subarray within an array (containing at least one number) which has the largest product.

Input: [2,3,-2,4]
Output: 6
Explanation: [2,3] has the largest product 6.
Input: [-2,0,-1]
Output: 0
Explanation: The result cannot be 2, because [-2,-1] is not a subarray.

#include <iostream>

using namespace std;

//求最大值

int max_num(int* input, int i, int j){

    int max = 1;

    for(int  k = i;k<j;k++)

       max*=input[k];

    return max;

}

//按负数划分

int split_neg_one(int* input, int i, int j){

    int num_neg = 0;

    for(int k = i;k<j;k++)

    {

cout<<"k-th num:"<<input[k]<<endl;

        if(input[k]<0)

            num_neg += 1;

    }

    cout<<"num of num_neg:"<< num_neg<<endl;

    if(num_neg % 2 == 0) //如果有偶数个-1

    {

    cout<<"even number"<<endl;

    return max_num(input,i,j);

}

else

{ //如果有奇数个-1

        int max = 0x80000000;

        for(int k = i;k<j;k++){

            if(input[k]<0){

                int temp = max_num(input,i,k)> max_num(input,k+1,j)?max_num(input,i,k): max_num(input,k+1,j);

      cout<<"split one i, k, temp:"<<i<<" "<<k<<" "<<temp<<endl;

                max = max>temp?max:temp;

            }

        }

         return max;

    }

}

//按0划分

int split_zero(int* input, int i , int j)

{

    int start = i;

    int max = 0x80000000;

    bool flag_zero = false;

    cout<<"begin"<<endl;

    for(int k = i; k<j;k++)

    {

        if(input[k]==0)

        {   

max = max > 0? max:0;

cout<<"zero position:"<<k<<endl;

                       flag_zero=true;

            if(k != i)

             {

                    int temp = split_neg_one(input,start,k);

    cout<<"split negtive one:"<<max<<endl;

                    max = max > temp ? max:temp;

   cout<<"max temp compare:"<<max<<endl;

                    start=k+1;

             }

         }

         if(k==j-1){

          int temp = split_neg_one(input,start,j);

          cout<<"split  last:"<<start<<" "<<j<<" temp:"<<temp<<endl;

            max = max > temp ? max:temp;

}

    }

    if(!flag_zero){

        max = split_neg_one(input,i,j);

       cout<<"point 1:"<<endl;

    }

    return max;

}

int process(int * input, int length){

    if(input==NULL || length < 0)

        return 0x80000000;

    split_zero(input,0,length);

}

int main() {

int input[]={2 , 3 ,2, 1, 0, 1, 4, -1, -2,-3,-4,-5};

int length = sizeof(input)/sizeof(int);

    cout <<"result:"<<process(input,length)<< endl;

}