4.1最大子数组问题

暴力求解Θ(n²)

#include <iostream>
using namespace std;

int lt, rt, sum;
int arr[4] = { 1,-4,3,-4};

void find_max()
{
    lt = 0, rt = 0;
    sum = -1e9;
    int current_sum;
    for (int i = 0; i < 4; i++)
    {
        current_sum = 0;
        for (int j = i; j < 4; j++)
        {
            current_sum += arr[j];
            if (sum < current_sum)
                sum = current_sum;
            lt = i, rt = j;
        }       
    }
}

int  main()
{
    find_max();
    cout<<sum;
    system("pause");
}