题解 | 喜欢切数组的红

#include <iostream>
#include<vector>
using namespace std;

int main() {
    int n;
    cin >> n;
    int num;
    vector <int> nums;
    int ni = n;
    int  sum=0;
    while (ni--) { // 注意 while 处理多个 case
        cin >> num;
        nums.push_back(num);
        sum+=num;
    }
    int count=0;if(sum%3){cout<<count;return 0;}
    int  sum1 = 0, sum2 = 0, sum3 = 0;
    bool b1 = false, b2 = false;
    for (int i = 0; i < n - 2; i++)
    {
        sum1 += nums[i];
        if (nums[i] > 0)b1 = true;
        if(sum1==sum/3&&b1)
        {
            for (int j = i + 1; j < n - 1; j++)
            {
                sum2 += nums[j];
                if (nums[j] > 0)b2 = true;
                if(sum2==sum/3&&b2)
                {
                    for (int k = j+1; k < n; k++)
                        if (nums[k] > 0){count++;break;}
                }
            }
            sum2=0;b2=false;
        }
    }
    cout << count << endl;
}