Roughly commit

Author: fibers

src/main/java/com/fibers/algorithm/datastructure/Calculator.java

@@ -0,0 +1,40 @@
+package com.fibers.algorithm.datastructure;
+
+import java.util.LinkedList;
+import java.util.Queue;
+import java.util.Stack;
+
+//TODO: Need fix
+public class Calculator {
+
+    public static int eval(String s) {
+        Queue<String> output = shuntingYard(s);
+        Stack<String> temp = new Stack<>();
+        int result = 0;
+        String token = null;
+        while ((token = output.poll()) != null) {
+            switch (token) {
+                case "+":
+                    result += (Integer.valueOf(temp.pop()) + Integer.valueOf(temp.pop()) );
+                default:
+                    temp.add(token);
+
+            }
+        }
+
+        return result;
+    }
+
+    public static Queue<String> shuntingYard(String s) {
+        Stack<String> operator = new Stack<>();
+        Queue<String> output = new LinkedList<>();
+
+
+        return output;
+    }
+
+    public String nextToken(char[] c, int index) {
+        return null;
+    }
+
+}

src/main/java/com/fibers/algorithm/datastructure/ListNode.java

@@ -9,7 +9,22 @@ public ListNode(int t) {
         val = t;
     }
 
-    public static void main(String[] args){
+    public static ListNode valueOf(int[] ar) {
+        if (ar == null || ar.length == 0) {
+            return null;
+        }
+
+        ListNode head = new ListNode(ar[0]);
+        ListNode p = head;
+        for (int i = 1; i<ar.length ;i++) {
+            ListNode temp = new ListNode(ar[i]);
+            p.next = temp;
+            p = p.next;
+        }
+        return head;
+    }
+
+    public static void main(String[] args) {
         System.out.println("aaaa");
     }
 

src/main/java/com/fibers/algorithm/leetcode/_061/Solution.java

@@ -1,4 +1,42 @@
 package com.fibers.algorithm.leetcode._061;
+
+import com.fibers.algorithm.datastructure.ListNode;
+import com.fibers.utils.Utils;
+
 public class Solution {
+
+    public static void main(String[] args) {
+        ListNode head = ListNode.valueOf(new int[]{1,2,3,4,5});
+
+        Solution s = new Solution();
+        Utils.printListNode(s.rotateRight(head, 2));
+    }
+
+    public ListNode rotateRight(ListNode head, int k) {
+        if (head == null || k == 0) {
+            return head;
+        }
+
+        ListNode p = head;
+        ListNode tail = null;
+        int size = 0;
+        while (p != null) {
+            size++;
+            tail = p;
+            p = p.next;
+        }
+
+        int index = size - k % size;
+        p = head;
+        while (--index > 0) {
+            p = p.next;
+        }
+
+        tail.next = head;
+        head = p.next;
+        p.next = null;
+
+        return head;
+    }
 }
-
+