火柴棍摆正方形

已知一个数组，保存了n个(n<=15)火柴棍，问能否使用这n个火柴棍摆成1个正方形?

代码实现:

---

#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
bool solution(int i, vector<int> &nums, int target, int bucket[])
{
    if(i >= nums.size())
    return (bucket[0] == target && bucket[1] == target
    && bucket[2] == target && bucket[3] == target);
    for(int j = 0; j < 4; j++)
    {
        if(bucket[j] + nums[i] > target)
        continue;
        bucket[j] += nums[i];
        if(solution(i+1, nums, target, bucket))
        return true;
        bucket[j] -= nums[i];
    }   
    return false;
}
int main()
{
    vector<int> a;
    int t,n;
    cin>>t;
    while(t--)
    {
        cin>>n;
        a.push_back(n);
    }
    if(a.size() < 4)
    {
        cout<<"false"<<endl;
        return 0;
    }
    int sum = 0;
    for(int i = 0; i < a.size(); i++)
    sum += a[i];
    if(sum % 4)
    {
        cout<<"false"<<endl;
        return 0;
    }
    int bucket[4] = {0};
    sort(a.rbegin(), a.rend());
    cout<<solution(0, a, sum/4, bucket)<<endl;
    return 0;
 }