作业

Week_02/id_12/242_12

@@ -0,0 +1,36 @@
+class Solution {
+
+    /**
+     * @param String $s
+     * @param String $t
+     * @return Boolean
+     */
+    function isAnagram($s, $t) {
+        $ttemp = $t;
+        $sLen = strlen($s);
+        $tLen = strlen($t);
+        if($sLen != $tLen){
+            return false;
+        }
+        $sbool = $tbool = true;
+        for($i=0;$i<$sLen;$i++){
+            if(stripos($t, $s[$i]) === false){
+                $sbool = false;
+                break;
+            } 
+            $t = preg_replace("/$s[$i]/", '', $t, 1);
+        }
+        for($j=0;$j<$tLen;$j++){ 
+            if(stripos($s, $ttemp[$j]) === false){
+                $tbool = false;
+                break;
+            }
+            $s = preg_replace("/$ttemp[$j]/", '', $s, 1);
+        }
+        if($sbool && $tbool){
+            return true;
+        }else{
+            return false;
+        }
+    }
+}

Week_02/id_12/671_12

@@ -0,0 +1,31 @@
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     int val;
+ *     TreeNode left;
+ *     TreeNode right;
+ *     TreeNode(int x) { val = x; }
+ * }
+ */
+class Solution {
+    public int findSecondMinimumValue(TreeNode root) {
+        return traversal(root,root.val);
+    }
+
+    private int traversal(TreeNode root,int value){
+        if(root == null){
+            return -1;
+        }
+        if(root.val > value){
+            return root.val;
+        }
+        int l = traversal(root.left,value);
+        int r = traversal(root.right,value);
+
+        if(l>=0 && r>=0){
+            return Math.min(l,r);
+        }
+        return Math.max(l,r);
+    }
+
+}