day 2

src/test/java/zuolaos/jichuban/Code06_链表相加.java

@@ -2,5 +2,74 @@ package zuolaos.jichuban;
 
 public class Code06_链表相加 {
 
-    
+    public static void main(String[] args) {
+        Node head1 = new Node(1);
+        head1.next=new Node(2);
+        head1.next.next=new Node(3);
+
+        Node head2 = new Node(1);
+        head2.next=new Node(2);
+        head2.next.next=new Node(9);
+
+        Node node = addTowNumbers(head1, head2);
+        System.out.println(node);
+
+
+    }
+    private static class Node {
+        int value;
+        Node next;
+
+        public Node(int value) {
+            this.value = value;
+        }
+    }
+
+    // 1 2 3   +  7 8 9 9 9 9 9   左边是个位
+    public static Node addTowNumbers(Node head1, Node head2) {
+
+        int len1 = getLen(head1);
+        int len2 = getLen(head2);
+        Node l = len1 >= len2 ? head1 : head2;
+        Node s = l == head1 ? head2 : head1;
+
+        Node curL=l;
+        Node curS=s;
+        int carry=0;
+        int curNum=0;
+        Node last =curL;
+        while (curS!=null){
+            curNum=curL.value+curS.value+carry;
+            curL.value=curNum % 10;
+            carry=curNum/10;
+            last=curL;
+            curL=curL.next;
+            curS=curS.next;
+        }
+
+        while (curL!=null){
+            curNum=curL.value+curS.value+carry;
+            curL.value=curNum % 10;
+            carry=curNum/10;
+            last=curL;
+            curL=curL.next;
+        }
+        if(carry>0){
+            last.next=new Node(1);
+        }
+        return l;
+    }
+
+
+    //求长度
+    public static int getLen(Node head) {
+        int count = 0;
+        while (head != null) {
+            count++;
+            head = head.next;
+        }
+        return count;
+    }
+
+
 }

src/test/java/zuolaos/jichuban/Code07_合并链表.java

@@ -0,0 +1,52 @@
+package zuolaos.jichuban;
+
+public class Code07_合并链表 {
+
+    public static void main(String[] args) {
+        Node head1 = new Node(0);
+        head1.next = new Node(2);
+        head1.next.next = new Node(3);
+
+        Node head2 = new Node(1);
+        head2.next = new Node(2);
+        head2.next.next = new Node(9);
+        Node node = mergeTowLists(head1, head2);
+        System.out.println(node);
+    }
+
+
+    private static Node mergeTowLists(Node head1, Node head2) {
+        if (head1 == null || head2 == null) {
+            return head1 == null ? head2 : head1;
+        }
+        Node head = head1.value <= head2.value ? head1 : head2;
+        Node cur1 = head.next;
+        Node cur2 = head == head1 ? head2 : head1;
+        Node pre = head;
+        while (cur1 != null && cur2 != null) {
+            if (cur1.value <= cur2.value) {
+                pre.next = cur1;
+                cur1 = cur1.next;
+            } else {
+                pre.next = cur2;
+                cur2 = cur2.next;
+            }
+            pre = pre.next;
+        }
+        pre.next = cur1 != null ? cur1 : cur2;
+
+        return head;
+    }
+
+
+    private static class Node {
+        int value;
+        Node next;
+
+        public Node(int value) {
+            this.value = value;
+        }
+    }
+
+
+}