feat: week 02-03 풀이 추가 (climbing-stairs, house-robber, product-of-array-except-self, valid-palindrome, number-of-1-bits)

01-binary · 01-binary · commit 2927ba55a54f · 2026-03-21T00:15:18.000+09:00
diff --git a/climbing-stairs/01-binary.js b/climbing-stairs/01-binary.js
@@ -0,0 +1,18 @@
+/**
+ * @param {number} n
+ * @return {number}
+ */
+
+var climbStairs = function (n) {
+  if (n === 1) return 1;
+  if (n === 2) return 2;
+  const arr = [0, 1, 2];
+  let i = 3;
+  while (i <= n) {
+    const temp = arr[i - 1] + arr[i - 2];
+    arr.push(temp);
+    i++;
+  }
+
+  return arr[n];
+};
diff --git a/house-robber/01-binary.js b/house-robber/01-binary.js
@@ -0,0 +1,19 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var rob = function (nums) {
+  const memo = new Map();
+  return dfs(nums, 0, memo);
+};
+
+const dfs = (nums, i, memo) => {
+  if (i >= nums.length) return 0;
+  if (memo.has(i)) return memo.get(i);
+  const result = Math.max(
+    nums[i] + dfs(nums, i + 2, memo),
+    dfs(nums, i + 1, memo),
+  );
+  memo.set(i, result);
+  return result;
+};
diff --git a/number-of-1-bits/01-binary.js b/number-of-1-bits/01-binary.js
@@ -0,0 +1,13 @@
+/**
+ * @param {number} n
+ * @return {number}
+ */
+var hammingWeight = function (n) {
+  let cnt = 1;
+  while (n >= 2) {
+    const r = n % 2;
+    n = Math.floor(n / 2);
+    if (r === 1) cnt++;
+  }
+  return cnt;
+};
diff --git a/product-of-array-except-self/01-binary.js b/product-of-array-except-self/01-binary.js
@@ -0,0 +1,24 @@
+/**
+ * @param {number[]} nums
+ * @return {number[]}
+ */
+var productExceptSelf = function (nums) {
+  const r = Array.from(nums.length);
+  const l = Array.from(nums.length);
+  const a = Array.from(nums.length);
+  for (let i = 0; i < nums.length; i++) {
+    const temp = r[i - 1] ?? 1;
+    const temp2 = nums[i - 1] ?? 1;
+    r[i] = temp * temp2;
+  }
+  for (let i = nums.length - 1; i > -1; i--) {
+    const temp = l[i + 1] ?? 1;
+    const temp2 = nums[i + 1] ?? 1;
+    l[i] = temp * temp2;
+  }
+  for (let i = 0; i < nums.length; i++) {
+    a[i] = l[i] * r[i];
+  }
+
+  return a;
+};
diff --git a/valid-palindrome/01-binary.js b/valid-palindrome/01-binary.js
@@ -0,0 +1,8 @@
+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+var isPalindrome = function (s) {
+  const result = s.toLowerCase().replace(/[^a-z0-9]/g, '');
+  return result === result.split('').reverse().join('');
+};
