nextcommit

Author: shashankch

src/revision/FindMaxinStack.java

@@ -0,0 +1,85 @@
+package revision;
+
+import java.util.Stack;
+
+public class FindMaxinStack {
+
+    Stack<Integer> stk = new Stack<>();
+    int max;
+
+    public void getMax() {
+
+        if (stk.empty()) {
+            System.out.println("no element");
+        } else {
+            System.out.println(max);
+        }
+    }
+
+    public void peek() {
+
+        if (stk.empty()) {
+            System.out.println("stack is empty");
+        }
+
+        int top = stk.peek();
+
+        if (top > max) { // here it means max contains the top element.
+            System.out.println(max);
+        } else {
+            System.out.println(top);
+        }
+
+    }
+
+
+    public void pop() {
+
+        if (stk.isEmpty()) {
+            System.out.println("empty");
+            return;
+        }
+
+        int top = stk.peek();
+        stk.pop();
+        if (top > max) {
+            System.out.println(max);
+            max = 2 * max - top;
+        } else {
+            System.out.println(top);
+        }
+
+    }
+
+
+    public void push(int elem) {
+
+        if (stk.isEmpty()) {
+
+            max = elem;
+            stk.push(elem);
+            return;
+        }
+
+        if (elem > max) {
+            stk.push(2 * elem - max);
+            max = elem;
+        } else {
+            stk.push(elem);
+        }
+
+
+    }
+
+
+    public static void main(String[] args) {
+
+        FindMaxinStack obj = new FindMaxinStack();
+        obj.push(3);
+        obj.pop();
+        obj.getMax();
+    }
+
+
+
+}