From e8cc89c5c5665e5176e6a144f915e9c05e63c638 Mon Sep 17 00:00:00 2001
From: Colston Bod-oy <75562733+ColstonBod-oy@users.noreply.github.com>
Date: Tue, 27 Jun 2023 17:49:40 +0800
Subject: [PATCH] Update 1143-longest-common-subsequence.java

Modified the iterative version to be bottom-up as well and removed unnecessary for loops.
---
 java/1143-longest-common-subsequence.java | 29 +++++++----------------
 1 file changed, 8 insertions(+), 21 deletions(-)

diff --git a/java/1143-longest-common-subsequence.java b/java/1143-longest-common-subsequence.java
index 59071919f..478745e8b 100644
--- a/java/1143-longest-common-subsequence.java
+++ b/java/1143-longest-common-subsequence.java
@@ -22,33 +22,20 @@ public int LCS(String s1, String s2, int i, int j, int[][] dp) {
 
 // Iterative version
 class Solution {
-
+    
     public int longestCommonSubsequence(String text1, String text2) {
-        //O(n*m)/O(n*m)  time/memory
-        if (text1.isEmpty() || text2.isEmpty()) {
-            return 0;
-        }
-
-        int[][] dp = new int[text1.length() + 1][text2.length() + 1];
-
-        for (int i = 0; i <= text1.length(); i++) {
-            dp[i][0] = 0;
-        }
-
-        for (int j = 0; j <= text2.length(); j++) {
-            dp[0][j] = 0;
-        }
+        int[][] dp = new int[text1.length() + 1][text2.length() + 1];    
 
-        for (int i = 1; i <= text1.length(); i++) {
-            for (int j = 1; j <= text2.length(); j++) {
-                if (text1.charAt(i - 1) == text2.charAt(j - 1)) {
-                    dp[i][j] = 1 + dp[i - 1][j - 1];
+        for (int i = text1.length() - 1; i >= 0; i--) {
+            for (int j = text2.length() - 1; j >= 0; j--) {
+                if (text1.charAt(i) == text2.charAt(j)) {
+                    dp[i][j] = 1 + dp[i + 1][j + 1];
                 } else {
-                    dp[i][j] = Math.max(dp[i][j - 1], dp[i - 1][j]);
+                    dp[i][j] = Math.max(dp[i][j + 1], dp[i + 1][j]);
                 }
             }
         }
 
-        return dp[text1.length()][text2.length()];
+        return dp[0][0];
     }
 }