题解 | 数组分组

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

bool check(vector<int> &nums,int sum,int i,int m)
{
    if(i==nums.size()-1)
    if(sum+nums[i]==m||sum-nums[i]==m)return true;
    else if(i==nums.size()-1)return false;
    return(check(nums,sum+nums[i],i+1,m)
    ||check(nums,sum-nums[i],i+1,m));
}

int main() {
    int n;int a=0,b=0,c=0;int num;
    vector<int> nums;
    cin>>n;
    while (n>0) { 
        n--;
        cin>>num;
        if(num%5==0)a+=num;
        else if(num%3==0)b+=num;
        else {c+=abs(num);nums.push_back(abs(num));}
    }
    int m=abs(a-b);
    if(m==c&&c==0){cout<<"true";return 0;}
    if(check (nums,0 ,0,m))cout <<"true";
    else cout<<"false";return 0;
}