212. 삼총사

import Foundation

func solution(_ number:[Int]) -> Int {
    
    
    var answer : Int = 0
    
    for i in 0..<number.count-2 {
        for j in i+1..<number.count-1 {
            for k in j+1..<number.count {
                if number[i]+number[j]+number[k] == 0 {
                    answer += 1
                }
            }
        }
    }
        
    return answer
}