update

8 Algorithms Analysis/递归.md

@@ -10,6 +10,7 @@
 
 > 自顶向下的递归，自底向上是迭代
 
+
 ## 斐波那契数列 
 
 fib(n)=fib(n-1)+fib(n-2)  
@@ -67,6 +68,62 @@ int fib(int n) {
 ```
 
 
+## 合并有序链表
+
+
+递归解法
+public static LinkedNode mergeSeqLink2(LinkedNode l1, LinkedNode l2){
+
+        if(l1 == null){
+            return l2;
+        }
+        if(l2 == null){
+            return l1;
+        }
+
+        if(l1.value < l2.value){
+            l1.next = mergeSeqLink2(l1.next,l2);
+            return l1;
+        }else{
+            l2.next = mergeSeqLink2(l2.next,l1);
+            return l2;
+        }
+    }
+```
+
+非递归解法
+```
+public static LinkedNode mergeSeqLink(LinkedNode l1, LinkedNode l2){
+        if (l1 == null) return l2;
+        if (l2 == null) return l1;
+
+        LinkedNode result = new LinkedNode(0);
+        LinkedNode tmp = result;
+
+        while (l1 != null && l2 != null) {
+            if (l1.value < l2.value) {
+                tmp.next = l1;
+                tmp = tmp.next; //tmp 指针前进
+                l1 = l1.next ; //l1 前进
+            } else {
+                tmp.next = l2;
+                l2 = l2.next;
+                tmp = tmp.next;
+            }
+        }
+
+        if (l1 != null) {
+            tmp.next = l1;
+        }
+
+        if (l2 != null) {
+            tmp.next = l2;
+        }
+
+        return result.next;
+    }
+```
+