From eb1a6438c2c322caf63bb8607a8be79e6f6515c6 Mon Sep 17 00:00:00 2001
From: jinvicky <jinvicky@intube.kr>
Date: Sun, 7 Sep 2025 11:25:23 +0900
Subject: [PATCH 1/3] longest common subsequence solution

---
 longest-common-subsequence/jinvicky.java | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 longest-common-subsequence/jinvicky.java

diff --git a/longest-common-subsequence/jinvicky.java b/longest-common-subsequence/jinvicky.java
new file mode 100644
index 000000000..eb8876388
--- /dev/null
+++ b/longest-common-subsequence/jinvicky.java
@@ -0,0 +1,21 @@
+class Solution {
+    public int longestCommonSubsequence(String text1, String text2) {
+        int m = text1.length();
+        int n = text2.length();
+
+        int[][] dp = new int[m+1][n+1];
+
+        for (int i = 0; i < m; i++) {
+            for (int j = 0; j < n; j++) {
+                // DP 계산을 +1로 했어야 했는데 이전 케이스를 재사용하는 -1로만 접근해서 범위 에러가 많이 났었다.
+                if (text1.charAt(i) == text2.charAt(j)) {
+                    dp[i + 1][j + 1] = dp[i][j] + 1;
+                } else {
+                    dp[i + 1][j + 1] = Math.max(dp[i][j + 1], dp[i + 1][j]);
+                }
+            }
+        }
+
+        return dp[m][n];
+    }
+}

From 7c6c91cf3af485ba9a9e6098910cd0f9d47775a5 Mon Sep 17 00:00:00 2001
From: jinvicky <jinvicky17@gmail.com>
Date: Tue, 9 Sep 2025 23:05:18 +0900
Subject: [PATCH 2/3] longest common subsequence solution

---
 longest-common-subsequence/jinvicky.java | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 longest-common-subsequence/jinvicky.java

diff --git a/longest-common-subsequence/jinvicky.java b/longest-common-subsequence/jinvicky.java
new file mode 100644
index 000000000..6e9a63155
--- /dev/null
+++ b/longest-common-subsequence/jinvicky.java
@@ -0,0 +1,18 @@
+class Solution {
+    public int longestCommonSubsequence(String text1, String text2) {
+        int m = text1.length();
+        int n = text2.length();
+        int[][] dp = new int[m + 1][n + 1];
+
+        for (int i = 1; i <= m; i++) {
+            for (int j = 1; j <= n; j++) {
+                if (text1.charAt(i - 1) == text2.charAt(j - 1)) {
+                    dp[i][j] = dp[i - 1][j - 1] + 1;  // 문자가 같으면 대각선 값 + 1
+                } else {
+                    dp[i][j] = Math.max(dp[i - 1][j], dp[i][j - 1]);  // 위 or 왼쪽 중 큰 값
+                }
+            }
+        }
+        return dp[m][n];
+    }
+}

From 8373128992aad2aad8ffd98fb2594cfe608345bd Mon Sep 17 00:00:00 2001
From: jinvicky <jinvicky17@gmail.com>
Date: Tue, 9 Sep 2025 23:06:38 +0900
Subject: [PATCH 3/3] longest common subsequence solution

---
 longest-common-subsequence/jinvicky.java | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/longest-common-subsequence/jinvicky.java b/longest-common-subsequence/jinvicky.java
index eb8876388..57a5da484 100644
--- a/longest-common-subsequence/jinvicky.java
+++ b/longest-common-subsequence/jinvicky.java
@@ -18,4 +18,23 @@ public int longestCommonSubsequence(String text1, String text2) {
 
         return dp[m][n];
     }
+
+    // -1을 참조해 이전 케이스를 재사용하는 경우는 1부터 m,n까지 하면 그렇게 할 수 있다.
+    public int longestCommonSubsequence2(String text1, String text2) {
+        int m = text1.length();
+        int n = text2.length();
+        int[][] dp = new int[m + 1][n + 1];
+
+        for (int i = 1; i <= m; i++) {
+            for (int j = 1; j <= n; j++) {
+                if (text1.charAt(i - 1) == text2.charAt(j - 1)) {
+                    dp[i][j] = dp[i - 1][j - 1] + 1;  // 문자가 같으면 대각선 값 + 1
+                } else {
+                    dp[i][j] = Math.max(dp[i - 1][j], dp[i][j - 1]);  // 위 or 왼쪽 중 큰 값
+                }
+            }
+        }
+
+        return dp[m][n];
+    }
 }