[프로그래머스/c++/swift] 삼총사

 

https://school.programmers.co.kr/learn/courses/30/lessons/131705

프로그래머스

 

 

c++ (1)

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


int ans = 0;
bool visit[14];

void BT(int cnt, int sum, int s, vector<int> number){
    if(cnt == 3){
        if(sum == 0) ans++;
        return;
    }
    for(int i=s; i<number.size(); i++){
        if(!visit[i]){
            visit[i] = true;
            BT(cnt+1, sum + number[i], i, number);
            visit[i] = false;
        }
    }
}

int solution(vector<int> number) {
    BT(0, 0, 0, number);
    return ans;
}

 

c++(2)

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

int solution(vector<int> number) {
    int ans = 0;
    for(int i=0; i<number.size(); i++){
        for(int j=i+1; j<number.size(); j++){
            for(int k=j+1; k<number.size(); k++){
                if(number[i] + number[j] + number[k] == 0) ans++;
            }
        }
    }
    return ans;
}

 

swift

import Foundation

func solution(_ number:[Int]) -> Int {
    var ans = 0
    for i in 0..<number.count {
        for j in i+1..<number.count {
            for k in j+1..<number.count {
                if number[i] + number[j] + number[k] == 0 {
                    ans += 1
                }
            }
        }
    }
    return ans
}