[WEEK05-2] 추슬기

doitchuu/AddBinary.js

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+/**
+ * @param {string} a
+ * @param {string} b
+ * @return {string}
+ */
+var addBinary = function(a, b) {
+    let i = a.length - 1;
+    let j = b.length - 1;
+    let carry = 0;
+    let result = "";
+
+    while (i >= 0 || j >= 0 || carry) {
+        let sum = carry;
+
+        if (i >= 0) sum += Number(a[i--]);
+        if (j >= 0) sum += Number(b[j--]);
+
+        result = String(sum % 2) + result;
+        carry =  Math.floor(sum / 2);
+    }
+
+    return result;
+};

doitchuu/DiameterOfBinaryTree.js

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+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number}
+ */
+var diameterOfBinaryTree = function(root) {
+    let diameter = 0;
+
+    function dfs(node) {
+        if (node === null) return 0;
+
+        const left = dfs(node.left);
+        const right = dfs(node.right);
+
+        diameter = Math.max(diameter, left + right);
+
+        return Math.max(left, right) + 1;
+    }
+
+    dfs(root);
+    return diameter;
+};