作业提交

Simona0769 · Simona0769 · commit 6fbfdd7c2699 · 2020-06-22T00:18:15.000+08:00
diff --git a/Week02/programming/n-ary-tree-preorder-traversal.js b/Week02/programming/n-ary-tree-preorder-traversal.js
@@ -0,0 +1,26 @@
+/**
+ * // Definition for a Node.
+ * function Node(val, children) {
+ *    this.val = val;
+ *    this.children = children;
+ * };
+ */
+
+/**
+ * @param {Node} root
+ * @return {number[]}
+ */
+var preorder = function(root) {
+    let nums = [] 
+    let  preorderFun = (node) => {
+        if (node) {
+            nums.push(node.val)
+            for (var i = 0; i < node.children.length; i ++) {
+                preorderFun(node.children[i])
+            }
+        }
+    }
+
+    preorderFun(root)
+    return nums
+};
diff --git a/Week02/programming/valid-anagram.js b/Week02/programming/valid-anagram.js
@@ -0,0 +1,55 @@
+/**
+ * 两个hashmap
+ * @param {string} s
+ * @param {string} t
+ * @return {boolean}
+ */
+var isAnagram = function(s, t) {
+    if (s.length !== t.length) {
+        return false
+    }
+    var hm1 = new Map();
+    var hm2 = new Map();
+    for (var i = 0; i < s.length; i ++) {
+        if (hm1.has(s[i])) {
+            hm1.set(s[i], hm1.get(s[i]) + 1)
+        } else {
+            hm1.set(s[i], 1)
+        }
+        if (hm2.has(t[i])) {
+            hm2.set(t[i], hm2.get(t[i]) + 1)
+        } else {
+            hm2.set(t[i], 1)
+        }
+    }
+    for(let key of hm1.keys()) {
+        if (!hm2.has(key) || hm2.get(key) !== hm1.get(key)) {
+            return false
+        }
+    }
+    return true
+};
+
+/**
+ * 计数器
+ * @param {string} s
+ * @param {string} t
+ * @return {boolean}
+ */
+var isAnagram = function(s, t) {
+    if (s.length !== t.length) {
+        return false
+    }
+    let counter = new Array(26).fill(0);
+    var aCode = 'a'.charCodeAt(0);
+    for (var i = 0; i < s.length; i ++) {
+        counter[s.charCodeAt(i) - aCode]++
+        counter[t.charCodeAt(i) - aCode]--
+    }
+    for(var j = 0; j < counter.length; j ++) {
+        if (counter[j] < 0) {
+            return false
+        }
+    }
+    return true
+};
