【Leetcode】 # 20 有效的括号 Rust Solution About Rust Stack implement
给定一个只包括 '('，')'，'{'，'}'，'['，']' 的字符串，判断字符串是否有效。
有效字符串需满足：
左括号必须用相同类型的右括号闭合。
左括号必须以正确的顺序闭合。
注意空字符串可被认为是有效字符串。
示例 1:
输入: "()"
输出: true
示例 2:
输入: "()[]{}"
输出: true
示例 3:
输入: "(]"
输出: false
示例 4:
输入: "([)]"
输出: false
示例 5:
输入: "{[]}"
输出: true
// lib.rs Rust Stack Implement
1 pub mod stack { 2 type Link<T> = Option<Box<StackNode<T>>>; 3 4 #[derive(Debug)] 5 pub struct Stack<T> { 6 top: Link<T>, 7 } 8 9 #[derive(Debug, Clone)] 10 struct StackNode<T> { 11 val: T, 12 next: Link<T>, 13 } 14 15 // impl <T> StackNode<T> { 16 // fn new(val: T) -> Self { 17 // StackNode { 18 // val, 19 // next: None, 20 // } 21 // } 22 // } 23 24 impl <T> Stack<T> { 25 pub fn new() -> Self { 26 Stack { top: None } 27 } 28 29 pub fn push(&mut self, val: T) { 30 // let mut node = StackNode::new(val); 31 // let next = self.top.take(); 32 // node.next = next; 33 // self.top = Some(Box::new(node)); 34 let new_node = Box::new(StackNode{ 35 val, 36 next: self.top.take(), 37 }); 38 39 self.top = Some(new_node); 40 } 41 42 pub fn pop(&mut self) -> Option<T> { 43 self.top 44 .take() 45 .map(|node| { 46 self.top = node.next; 47 node.val 48 }) 49 } 50 51 pub fn peek(&self) -> Option<&T> { 52 self.top 53 .as_ref() 54 .map(|node| 55 &node.val 56 ) 57 } 58 59 pub fn peek_mut(&mut self) -> Option<&mut T> { 60 self.top 61 .as_mut() 62 .map(|node| { 63 &mut node.val 64 }) 65 } 66 67 pub fn is_empty(&self) -> bool { 68 match self.peek() { 69 None => true, 70 Some(_) => false, 71 } 72 } 73 } 74 75 76 impl<T> Drop for Stack<T> { 77 fn drop(&mut self) { 78 let mut cut_link = self.top.take(); 79 while let Some(mut boxed_node) = cut_link{ 80 cut_link = boxed_node.next.take(); 81 } 82 } 83 } 84 85 #[cfg(test)] 86 mod test { 87 use super::Stack; 88 #[test] 89 fn basic() { 90 let mut s = Stack::<i32>::new(); 91 92 assert_eq!(s.pop(), None); 93 s.push(1); 94 s.push(2); 95 s.push(3); 96 97 println!("s = {:?}", s); 98 99 assert_eq!(s.pop(), Some(3)); 100 assert_eq!(s.pop(), Some(2)); 101 assert_eq!(s.pop(), Some(1)); 102 assert_eq!(s.pop(), None); 103 } 104 105 #[test] 106 fn peek() { 107 let mut s = Stack::new(); 108 109 assert_eq!(s.peek(), None); 110 assert_eq!(s.peek_mut(), None); 111 s.push(1); 112 s.push(2); 113 s.push(3); 114 115 assert_eq!(s.peek(), Some(&3)); 116 assert_eq!(s.peek_mut(), Some(&mut 3)); 117 118 s.peek_mut().map(|val| { 119 *val = 34; 120 }); 121 assert_eq!(s.peek(), Some(&34)); 122 assert_eq!(s.pop(), Some(34)); 123 } 124 } 125 }
1 extern crate valid_parentheses; 2 3 use std::collections::HashMap; 4 use valid_parentheses::stack::Stack; 5 6 fn is_valid(s: String) -> bool{ 7 8 let mut hashmap = HashMap::new(); 9 hashmap.insert('(', ')'); 10 hashmap.insert('{', '}'); 11 hashmap.insert('[', ']'); 12 hashmap.insert('#', '#'); 13 hashmap.insert(')', '#'); 14 hashmap.insert('}', '#'); 15 hashmap.insert(']', '#'); 16 17 let temp_vec = s.chars().collect::<Vec<char>>(); 18 let mut temp_stack = Stack::<char>::new(); 19 20 for item in temp_vec { 21 if item == '(' || item == '{' || item == '[' { 22 temp_stack.push(item); 23 24 } else if item == ')' || item == '}' || item == ']' { 25 let temp = temp_stack.peek().unwrap_or(&'#'); 26 let rhs_temp = hashmap.get(temp); 27 if *rhs_temp.unwrap() == item { 28 temp_stack.pop(); 29 } else { 30 temp_stack.push(item); 31 } 32 } 33 } 34 35 temp_stack.is_empty() 36 } 37 38 39 fn main() { 40 41 // let s = String::from("]"); 42 let s = "([)]".to_owned(); 43 let ret = is_valid(s); 44 println!("ret = {}", ret); 45 }
Github Link : https://github.com/DaviRain-Su/leetcode_solution/blob/master/valid_parentheses/src/main.rs
