幸运的袋子（递归+回溯）

目录

一、题目

二、代码

---

一、题目

幸运的袋子__牛客网

二、代码

#include 
#include 
#include 
using namespace std;

static int _count = 0;
static int sum = 0;
static int product = 1;

void Combination(vector& v, int start)
{
    for (int i = start; i < v.size(); i++)
    {
        sum += v[i];
        product *= v[i];

        if (sum > product)
        {
            _count++;
            Combination(v, i + 1);
        }
        else if (v[i] == 1)
        {
            Combination(v, i + 1);
        }
        else
        {
            //回溯
            sum -= v[i];
            product /= v[i];
            break;
        }
        //回溯
        sum -= v[i];
        product /= v[i];

        for (; i + 1 < v.size() && v[i] == v[i + 1]; i++);
    }
}

int main()
{
    int n;
    cin >> n;
    vector data;

    for (int i = 0; i < n; i++)
    {
        int x;
        cin >> x;
        data.push_back(x);
    }

    sort(data.begin(), data.end());
    Combination(data, 0);
    cout << _count;

    return 0;
}