modify code

Author: algorithmzuo

src/class04/Code01_ReverseList.java

@@ -175,6 +175,11 @@ public static boolean checkDoubleListReverse(List<Integer> origin, DoubleNode he
 		return true;
 	}
 
+	
+	public static void f(Node head) {
+		head = head.next;
+	}
+	
 	// for test
 	public static void main(String[] args) {
 		int len = 50;

src/class04/Code04_ReverseNodesInKGroup.java

@@ -15,8 +15,10 @@ public static ListNode reverseKGroup(ListNode head, int k) {
 		if (end == null) {
 			return head;
 		}
+		// 第一组凑齐了！
 		head = end;
 		reverse(start, end);
+		// 上一组的结尾节点
 		ListNode lastEnd = start;
 		while (lastEnd.next != null) {
 			start = lastEnd.next;

src/class04/Code05_AddTwoNumbers.java

@@ -49,6 +49,7 @@ public static ListNode addTwoNumbers(ListNode head1, ListNode head2) {
 		return l;
 	}
 
+	// 求链表长度
 	public static int listLength(ListNode head) {
 		int len = 0;
 		while (head != null) {

src/class04/Code06_MergeTwoSortedLinkedList.java

@@ -9,13 +9,13 @@ public static class ListNode {
 		public ListNode next;
 	}
 
-	public static ListNode mergeTwoLists(ListNode l1, ListNode l2) {
-		if (l1 == null || l2 == null) {
-			return l1 == null ? l2 : l1;
+	public static ListNode mergeTwoLists(ListNode head1, ListNode head2) {
+		if (head1 == null || head2 == null) {
+			return head1 == null ? head2 : head1;
 		}
-		ListNode head = l1.val <= l2.val ? l1 : l2;
+		ListNode head = head1.val <= head2.val ? head1 : head2;
 		ListNode cur1 = head.next;
-		ListNode cur2 = head == l1 ? l2 : l1;
+		ListNode cur2 = head == head1 ? head2 : head1;
 		ListNode pre = head;
 		while (cur1 != null && cur2 != null) {
 			if (cur1.val <= cur2.val) {