백준 2798 C++

#include <iostream>
using namespace std;

int main(){
    int card_num;
    int max_num = 0;
    int sum = 0, S_sum = 0;
    int arr[100]= {0,};
    cin >> card_num >> max_num;
    for(int i=0; i<card_num; i++){
        cin >> arr[i];
    }    
    for(int i=0; i<card_num-2; i++){
        for(int j=i+1; j<card_num-1; j++){
            for(int k=j+1; k<card_num; k++){
                sum = arr[i] + arr[j] + arr[k];
                if(sum <= max_num){
                    if(S_sum < sum){
                        S_sum = sum;
                    }
                }
            }
        }
    }

    cout << S_sum;
    return 0;
}