0020 by HashMap

Author: KevinLvLight

0020v2.java

@@ -0,0 +1,19 @@
+class Solution {
+  //取自一个评论，侵删
+  HashMap<Character, Character> paranthesesMap = new HashMap<>();
+      
+  public Solution(){
+    this.paranthesesMap.put('(', ')');
+    this.paranthesesMap.put('[', ']');
+    this.paranthesesMap.put('{', '}');  
+  }
+  
+  public boolean isValid(String s) {
+    Stack<Character> myStack = new Stack<Character>();
+    for(char c: s.toCharArray()) {
+      if (paranthesesMap.keySet().contains(c)) myStack.push(paranthesesMap.get(c));
+      else if (myStack.isEmpty() || c != myStack.pop()) return false;  
+    }  
+    return myStack.isEmpty();     
+  }
+}