From 6acd81cc36c014f84e16df1b351c3d64ac2e7e0d Mon Sep 17 00:00:00 2001
From: JangAyeon <ayeon3052@ewhain.net>
Date: Tue, 25 Nov 2025 07:11:35 +0900
Subject: [PATCH 1/5] solve combination-sum [dfs]

---
 combination-sum/JangAyeon.js | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 combination-sum/JangAyeon.js

diff --git a/combination-sum/JangAyeon.js b/combination-sum/JangAyeon.js
new file mode 100644
index 0000000000..ba12a19eeb
--- /dev/null
+++ b/combination-sum/JangAyeon.js
@@ -0,0 +1,23 @@
+/**
+ * @param {number[]} candidates
+ * @param {number} target
+ * @return {number[][]}
+ */
+var combinationSum = function (arr, target) {
+  const N = arr.length;
+  const answer = [];
+  function dfs(total, idx, route) {
+    if (total >= target) {
+      if (total == target) {
+        answer.push(route);
+      }
+      return;
+    }
+    for (let i = idx; i < N; i++) {
+      dfs(total + arr[i], i, [...route, arr[i]]);
+    }
+  }
+
+  dfs(0, 0, []);
+  return answer;
+};

From bac506f5285d6d0351230e3c1b789813c5fcd5e8 Mon Sep 17 00:00:00 2001
From: JangAyeon <ayeon3052@ewhain.net>
Date: Tue, 25 Nov 2025 07:13:39 +0900
Subject: [PATCH 2/5] solve number of 1 bit [rest operation + sum reduce]

---
 number-of-1-bits/JangAyeon.js | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 number-of-1-bits/JangAyeon.js

diff --git a/number-of-1-bits/JangAyeon.js b/number-of-1-bits/JangAyeon.js
new file mode 100644
index 0000000000..1ace955950
--- /dev/null
+++ b/number-of-1-bits/JangAyeon.js
@@ -0,0 +1,21 @@
+/**
+ * @param {number} n
+ * @return {number}
+ */
+var hammingWeight = function (n) {
+  function calDivision(num) {
+    return { v: Math.floor(num / 2), rest: num % 2 };
+  }
+  let num = n;
+  let result = 0;
+  while (true) {
+    const { v, rest } = calDivision(num);
+    result += rest;
+    if (v == 0) {
+      break;
+    }
+    num = v;
+  }
+
+  return result;
+};

From 9dc2b08f515f64a4b5c8ab67f7e7c77e54bb8d5c Mon Sep 17 00:00:00 2001
From: JangAyeon <ayeon3052@ewhain.net>
Date: Tue, 25 Nov 2025 07:15:12 +0900
Subject: [PATCH 3/5] solve valid palindrom [sliding window + chatCodeAt]

---
 valid-palindrome/JangAyeon.js | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 valid-palindrome/JangAyeon.js

diff --git a/valid-palindrome/JangAyeon.js b/valid-palindrome/JangAyeon.js
new file mode 100644
index 0000000000..4760f29e63
--- /dev/null
+++ b/valid-palindrome/JangAyeon.js
@@ -0,0 +1,20 @@
+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+var isPalindrome = function (s) {
+  const sLowered = [...s.toLowerCase().replace(" ", "")];
+  const isAlpha = (item) => item.charCodeAt() >= 97 && item.charCodeAt() <= 122;
+  const isNumber = (item) => item.charCodeAt() >= 48 && item.charCodeAt() <= 57;
+  const str = sLowered.filter((c) => isAlpha(c) || isNumber(c));
+  const N = str.length;
+  let [start, end] = [0, N - 1];
+  while (start <= end) {
+    if (str[start] != str[end]) {
+      return false;
+    }
+    start++;
+    end--;
+  }
+  return true;
+};

From 76d6b82a9f153fd5d281d770077e28ed7d8c630b Mon Sep 17 00:00:00 2001
From: JangAyeon <ayeon3052@ewhain.net>
Date: Tue, 25 Nov 2025 22:51:30 +0900
Subject: [PATCH 4/5] solve maxium sub array solve [dp]

---
 maximum-subarray/JangAyeon.js | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 maximum-subarray/JangAyeon.js

diff --git a/maximum-subarray/JangAyeon.js b/maximum-subarray/JangAyeon.js
new file mode 100644
index 0000000000..de25e24b90
--- /dev/null
+++ b/maximum-subarray/JangAyeon.js
@@ -0,0 +1,19 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var maxSubArray = function (nums) {
+  let pointer = nums[0];
+  let answer = pointer;
+  const N = nums.length;
+  for (let idx = 1; idx < N; idx++) {
+    if (nums[idx] > pointer + nums[idx]) {
+      pointer = nums[idx];
+    } else {
+      pointer += nums[idx];
+    }
+    // console.log(idx, pointer)
+    answer = Math.max(pointer, answer);
+  }
+  return answer;
+};

From 5e78fe8a746ac319384c0fb6bf132c94c77adcbc Mon Sep 17 00:00:00 2001
From: JangAyeon <ayeon3052@ewhain.net>
Date: Fri, 28 Nov 2025 07:55:51 +0900
Subject: [PATCH 5/5] solve decode way [dp]

---
 decode-ways/JangAyeon.js | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 decode-ways/JangAyeon.js

diff --git a/decode-ways/JangAyeon.js b/decode-ways/JangAyeon.js
new file mode 100644
index 0000000000..0bad90be6b
--- /dev/null
+++ b/decode-ways/JangAyeon.js
@@ -0,0 +1,23 @@
+var numDecodings = function (s) {
+  const N = s.length;
+  const memo = {};
+
+  function dfs(i) {
+    if (i === N) return 1;
+    if (s[i] === "0") return 0; // 0은 단독으로 decode 불가능
+    if (memo[i] !== undefined) return memo[i];
+
+    // 1자리
+    let count = dfs(i + 1);
+
+    // 2자리
+    if (i + 1 < N && Number(s.slice(i, i + 2)) <= 26) {
+      count += dfs(i + 2);
+    }
+
+    memo[i] = count;
+    return count;
+  }
+
+  return dfs(0);
+};