stack

Author: Simcoderan

Hard1106.java

@@ -0,0 +1,58 @@
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Stack;
+
+
+    class Hard1106{
+    public char evalExpr(char op, List<Character> list){
+        if (op =='!'){
+            return list.get(0)=='t'?'f':'t';
+
+        }
+        else if (op == '&'){
+            for (char c: list){
+                if(c=='f'){
+                    return 'f';
+                }
+            }
+            return 't';
+        } else if (op =='|'){
+              for (char c: list){
+                if(c=='t'){
+                    return 't';
+                }
+              }
+              return 'f';
+        }
+        return 'f';
+
+    }
+    public boolean parseBoolExpr(String expression) {
+        //"!(&(f,t))"
+        Stack<Character> stack = new Stack<>();
+
+        for (char c:expression.toCharArray()){
+            if (c == ')'){
+                List<Character>list=new ArrayList<>();
+            while (stack.peek() != '('){
+                list.add(stack.pop());
+
+            }
+            stack.pop();
+            char op=stack.pop();
+            char res= evalExpr(op,list);
+            stack.push(res);
+
+            } else if (c !=','){
+                stack.push(c);
+
+            }
+
+        }
+        return stack.peek() == 't'? true : false;
+
+        
+    }
+}
+    
+