From b5568e66664858cbf3b6b67fb2bd9b138359e55c Mon Sep 17 00:00:00 2001
From: Nikitha Reddy <nikithareddy1103@gmail.com>
Date: Wed, 12 Feb 2025 18:17:21 +0530
Subject: [PATCH] Update WordSearch79.java

---
 src/WordSearch79.java | 124 +++++++-----------------------------------
 1 file changed, 19 insertions(+), 105 deletions(-)

diff --git a/src/WordSearch79.java b/src/WordSearch79.java
index 87221d3..ef83ad4 100644
--- a/src/WordSearch79.java
+++ b/src/WordSearch79.java
@@ -20,116 +20,30 @@
  */
 
 
-public class WordSearch79 {
-    public boolean exist(char[][] board, String word) {
-
-        if (word.length() == 0) {
-            return true;
-        }
-
-        if (board.length == 0) {
-            return false;
-        }
-
-        int m = board.length;
-        int n = board[0].length;
-
-        for (int i = 0; i < m; i++) {
-            for (int j = 0; j < n; j++) {
-                boolean[][] visited = new boolean[m][n];
-                if (helper(i, j, 0, board, word, visited)) {
-                    return true;
-                }
-            }
-        }
-
-        return false;
-
-    }
-
-
-    private boolean helper(int i, int j, int index, char[][] board, String word, boolean[][] visited) {
-        if (index >= word.length()) {
-            return true;
-        }
-
-        if (i < 0 || i >= board.length || j < 0 || j >= board[0].length) {
-            return false;
-        }
-
-        if (visited[i][j] || board[i][j] != word.charAt(index)) {
-            return false;
-        }
-
-        visited[i][j] = true;
-
-        if (helper(i, j+1, index + 1, board, word, visited) ||
-                helper(i+1, j, index + 1, board, word, visited) ||
-                helper(i, j-1, index + 1, board, word, visited) ||
-                helper(i-1, j, index + 1, board, word, visited)) {
-            return true;
-        }
-
-        visited[i][j] = false;
-
-        return false;
-    }
-
-
-    /**
-     * https://discuss.leetcode.com/topic/7907/accepted-very-short-java-solution-no-additional-space
-     */
-    public boolean exist2(char[][] board, String word) {
-
-        if (word.length() == 0) {
-            return true;
-        }
-
-        if (board.length == 0) {
-            return false;
-        }
-
-        int m = board.length;
-        int n = board[0].length;
-
-        for (int i = 0; i < m; i++) {
-            for (int j = 0; j < n; j++) {
-                if (helper(i, j, 0, board, word)) {
+Class Solution{
+    public boolean exist(char board[][],String word){
+        for(int i=0;i<board.length;i++){
+            for(int j=0;j<board[0].length;j++){
+                if(dfs(board,word,i,j,0)){
                     return true;
                 }
             }
         }
-
         return false;
-
     }
-
-
-    private boolean helper(int i, int j, int index, char[][] board, String word) {
-        if (index >= word.length()) {
-            return true;
-        }
-
-        if (i < 0 || i >= board.length || j < 0 || j >= board[0].length) {
-            return false;
-        }
-
-        if (board[i][j] != word.charAt(index)) {
-            return false;
-        }
-
-        board[i][j] ^= 256;
-
-        if (helper(i, j+1, index + 1, board, word) ||
-                helper(i+1, j, index + 1, board, word) ||
-                helper(i, j-1, index + 1, board, word) ||
-                helper(i-1, j, index + 1, board, word)) {
-            return true;
-        }
-
-        board[i][j] ^= 256;
-
-        return false;
+    public boolean dfs(char board[][],String word,int i,int j,int index){
+        if(index==word.length())return true;
+        if(i<0  || i>=board.length || j<0 || j>=board.length||board[i][j]!=word.charAt(i))return false;
+        char temp=board[i][j];
+        board[i][j]="#";
+        boolean found=dfs(board,word,i-1,j,index+1)||
+                    dfs(board,word,i+1,j,index+1)||
+            dfs(board,word,i,j-1,index+1)||
+            dfs(board,word,i,j-1,index+1);
+        board[i][j]=temp;
+        return found;
     }
-
 }
+        
+        
+