diff --git a/problems/0020.有效的括号.md b/problems/0020.有效的括号.md index 7bb7f746..a0df0d07 100644 --- a/problems/0020.有效的括号.md +++ b/problems/0020.有效的括号.md @@ -400,6 +400,27 @@ bool isValid(char * s){ return !stackTop; } ``` - +Scala: +```scala +object Solution { + import scala.collection.mutable + def isValid(s: String): Boolean = { + if(s.length % 2 != 0) return false // 如果字符串长度是奇数直接返回false + val stack = mutable.Stack[Char]() + // 循环遍历字符串 + for (i <- s.indices) { + val c = s(i) + if (c == '(' || c == '[' || c == '{') stack.push(c) + else if(stack.isEmpty) return false // 如果没有(、[、{则直接返回false + // 以下三种情况,不满足则直接返回false + else if(c==')' && stack.pop() != '(') return false + else if(c==']' && stack.pop() != '[') return false + else if(c=='}' && stack.pop() != '{') return false + } + // 如果为空则正确匹配,否则还有余孽就不匹配 + stack.isEmpty + } +} +``` -----------------------
diff --git a/problems/1047.删除字符串中的所有相邻重复项.md b/problems/1047.删除字符串中的所有相邻重复项.md index 638c8f4e..a92a3911 100644 --- a/problems/1047.删除字符串中的所有相邻重复项.md +++ b/problems/1047.删除字符串中的所有相邻重复项.md @@ -374,6 +374,27 @@ func removeDuplicates(_ s: String) -> String { return String(stack) } ``` - +Scala: +```scala +object Solution { + import scala.collection.mutable + def removeDuplicates(s: String): String = { + var stack = mutable.Stack[Int]() + var str = "" // 保存最终结果 + for (i <- s.indices) { + var tmp = s(i) + // 如果栈非空并且栈顶元素等于当前字符,那么删掉栈顶和字符串最后一个元素 + if (!stack.isEmpty && tmp == stack.head) { + str = str.take(str.length - 1) + stack.pop() + } else { + stack.push(tmp) + str += tmp + } + } + str + } +} +``` -----------------------