swift 第7课堆栈和队列

Posted 2021-05-19

import Foundation
import Glibc

public func solution(_ S : inout String) -> Int {
    let N = S.characters.count
    guard N != 0 else { return 1 }
    guard N % 2 == 0 else { return 0 }

    var cnt = 0
    for char in S.characters {
        if char == "(" {
            cnt += 1
        } else {
            guard cnt > 0 else { return 0 }
            cnt -= 1
        }
    }
    
    return cnt == 0 ? 1 : 0
}