Merge pull request #497 from Satvik782/satvik782

Added Java Valid Parentheses

Author: akkupy

java/Valid Parentheses.java

@@ -0,0 +1,47 @@
+class Solution {
+    public boolean isValid(String s) {
+        
+        ArrayDeque<Character> dq = new ArrayDeque<Character>(s.length());
+        
+        boolean valid = false;
+        
+        int i;
+        for(i=0;i<s.length();i++){
+            char c = s.charAt(i);
+
+            if(c=='(' || c=='{' || c=='['){
+                dq.add(c);
+            }
+            
+            if(dq.isEmpty()){
+                return true;
+            }
+            
+            if(c=='}' && dq.getLast() != '{'){
+                return false;
+            }
+            else{
+                dq.removeLast();
+            }
+            
+             if(c==')' && dq.getLast() != '('){
+                return false;
+            }
+            else{
+                dq.removeLast();
+            }
+            
+             if(c==']' && dq.getLast() != '['){
+                return false;
+            }
+            else{
+                dq.removeLast();
+            }
+            
+        }
+        
+        
+        
+        return (true);
+    }
+}