add Easy_83_Remove_Duplicates_from_Sorted_List

Author: zongyanqi

Easy_83_Remove_Duplicates_from_Sorted_List.js

@@ -0,0 +1,67 @@
+/**
+ *
+ * Given a sorted linked list, delete all duplicates such that each element appear only once.
+ *
+ * For example,
+ * Given 1->1->2, return 1->2.
+ * Given 1->1->2->3->3, return 1->2->3.
+ *
+ */
+
+
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val) {
+ *     this.val = val;
+ *     this.next = null;
+ * }
+ */
+
+/**
+ * @param {ListNode} head
+ * @return {ListNode}
+ */
+var deleteDuplicates = function (head) {
+
+    var p = head;
+    if (!p) return p;
+    var all = [p.val];
+    var t = p.next;
+
+    while (t) {
+
+        if (all.indexOf(t.val) == -1) {
+            all.push(t.val);
+            p = t;
+            t = p.next;
+        } else {
+            t = t.next;
+            p.next = t;
+        }
+    }
+    return head;
+
+};
+
+/**
+ * 改进方案
+ *
+ * @param {ListNode} head
+ * @return {ListNode}
+ */
+var deleteDuplicates2 = function (head) {
+
+    var p = head;
+    while (p && p.next) {
+        if (p.val == p.next.val) {
+            p.next = p.next.next;
+        } else {
+            p = p.next;
+        }
+    }
+    return head;
+
+};
+
+
+