From 95555e7221474c182986f4d4386c1626aa53786d Mon Sep 17 00:00:00 2001
From: robin <nowrobin3@gmail.com>
Date: Wed, 18 Mar 2026 03:59:37 +0900
Subject: [PATCH 1/5] valid-palindrome

---
 valid-palindrome/nowrobin.js | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 valid-palindrome/nowrobin.js

diff --git a/valid-palindrome/nowrobin.js b/valid-palindrome/nowrobin.js
new file mode 100644
index 000000000..86049f76c
--- /dev/null
+++ b/valid-palindrome/nowrobin.js
@@ -0,0 +1,23 @@
+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+var isPalindrome = function(s) {
+    // 1. 소문자로 변환 + 알파벳/숫자만 남기기
+    // (공백, 특수문자 제거)
+    s = s.toLowerCase().replace(/[^a-z0-9]/g, "");
+
+    const length = s.length;
+
+    // 2. 문자열의 절반만 순회하면서 양쪽 비교
+    for (let i = 0; i < length / 2; i++) {
+        // 왼쪽(i) vs 오른쪽(length - 1 - i)
+        if (s[i] !== s[length - 1 - i]) {
+            // 하나라도 다르면 팰린드롬 아님
+            return false;
+        }
+    }
+
+    // 3. 끝까지 문제 없으면 팰린드롬
+    return true;
+};
\ No newline at end of file

From 7b3401fdd44f6afc1f122b4dd4f63684d44460a8 Mon Sep 17 00:00:00 2001
From: robin <nowrobin3@gmail.com>
Date: Wed, 18 Mar 2026 04:07:40 +0900
Subject: [PATCH 2/5] number of 1 bits solution

---
 number-of-1-bits/nowrobin.js | 21 +++++++++++++++++++++
 valid-palindrome/nowrobin.js |  2 +-
 2 files changed, 22 insertions(+), 1 deletion(-)
 create mode 100644 number-of-1-bits/nowrobin.js

diff --git a/number-of-1-bits/nowrobin.js b/number-of-1-bits/nowrobin.js
new file mode 100644
index 000000000..cf33dc9b8
--- /dev/null
+++ b/number-of-1-bits/nowrobin.js
@@ -0,0 +1,21 @@
+/**
+ * @param {number} n - 32비트 정수
+ * @return {number} - 이진수에서 1의 개수
+ */
+var hammingWeight = function(n) {
+    let setBitCount = 0; // 1의 개수를 저장할 변수
+
+    // n이 0이 될 때까지 반복 (모든 1비트를 제거할 때까지)
+    while (n !== 0) {
+        // 가장 오른쪽에 있는 1비트를 제거
+        // 예: 101100 -> 101000
+        n &= (n - 1);
+
+        // 1비트 하나 제거했으므로 카운트 증가
+        setBitCount++;
+    }
+
+    // 총 1의 개수 반환
+    return setBitCount;
+};
+
diff --git a/valid-palindrome/nowrobin.js b/valid-palindrome/nowrobin.js
index 86049f76c..cc4fdecae 100644
--- a/valid-palindrome/nowrobin.js
+++ b/valid-palindrome/nowrobin.js
@@ -20,4 +20,4 @@ var isPalindrome = function(s) {
 
     // 3. 끝까지 문제 없으면 팰린드롬
     return true;
-};
\ No newline at end of file
+};

From 6c7ec079ee566712de6d9e1cc7a6dc4a8c19fa7f Mon Sep 17 00:00:00 2001
From: robin <nowrobin3@gmail.com>
Date: Sat, 21 Mar 2026 21:42:58 +0900
Subject: [PATCH 3/5] decode ways solution

---
 decode-ways/nowrobin.js | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 decode-ways/nowrobin.js

diff --git a/decode-ways/nowrobin.js b/decode-ways/nowrobin.js
new file mode 100644
index 000000000..634a8d1f8
--- /dev/null
+++ b/decode-ways/nowrobin.js
@@ -0,0 +1,30 @@
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var numDecodings = function(s) {
+    if (!s || s[0] === '0') {
+        return 0;
+    }
+
+    const n = s.length;
+    const dp = new Array(n + 1).fill(0);
+    dp[0] = 1;
+    dp[1] = 1;
+
+    for (let i = 2; i <= n; ++i) {
+        const oneDigit = parseInt(s[i - 1]);
+        const twoDigits = parseInt(s.substring(i - 2, i));
+
+        if (oneDigit !== 0) {
+            dp[i] += dp[i - 1];
+        }
+
+        if (10 <= twoDigits && twoDigits <= 26) {
+            dp[i] += dp[i - 2];
+        }
+    }
+
+    return dp[n];
+};
+

From 417109ed71df553fc767b5034cb11658a4523a66 Mon Sep 17 00:00:00 2001
From: robin <nowrobin3@gmail.com>
Date: Sat, 21 Mar 2026 21:47:37 +0900
Subject: [PATCH 4/5] combination-sum

---
 combination-sum/nowrobin.js | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 combination-sum/nowrobin.js

diff --git a/combination-sum/nowrobin.js b/combination-sum/nowrobin.js
new file mode 100644
index 000000000..8082fa7f2
--- /dev/null
+++ b/combination-sum/nowrobin.js
@@ -0,0 +1,22 @@
+/**
+ * @param {number[]} candidates
+ * @param {number} target
+ * @return {number[][]}
+ */
+function combinationSum(candidates, target) {
+  var buffer = [];
+  var result = [];
+  search(0, target);
+  return result;
+
+  function search(startIdx, target) {
+    if (target === 0) return result.push(buffer.slice());
+    if (target < 0) return;
+    if (startIdx === candidates.length) return;
+    buffer.push(candidates[startIdx]);
+    search(startIdx, target - candidates[startIdx]);
+    buffer.pop();
+    search(startIdx + 1, target);
+  }
+};
+

From fc25046ed56a51dd927f6dbc1dd437e51f0db423 Mon Sep 17 00:00:00 2001
From: robin <nowrobin3@gmail.com>
Date: Sat, 21 Mar 2026 22:09:30 +0900
Subject: [PATCH 5/5] max subarray

---
 maximum-subarray/nowrobin.js | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 maximum-subarray/nowrobin.js

diff --git a/maximum-subarray/nowrobin.js b/maximum-subarray/nowrobin.js
new file mode 100644
index 000000000..99d55523e
--- /dev/null
+++ b/maximum-subarray/nowrobin.js
@@ -0,0 +1,25 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var maxSubArray = function(nums) {
+    if (!nums || nums.length === 0) {
+        return 0;
+    }
+
+    // max_so_far: overall maximum sum
+    let max_so_far = nums[0];
+    
+    // max_ending_here: max sum of subarray ending at current position
+    let max_ending_here = nums[0];
+
+    for (let i = 1; i < nums.length; i++) {
+        // Core decision: start new or extend previous
+        max_ending_here = Math.max(nums[i], max_ending_here + nums[i]);
+
+        // Update overall maximum
+        max_so_far = Math.max(max_so_far, max_ending_here);
+    }
+
+    return max_so_far;
+};