Create main.cpp

Author: JawadSher

22 - Backtracking Algorithm Based Problems/01 - Rat in a Maze/main.cpp

@@ -0,0 +1,49 @@
+class Solution {
+  public:
+    bool isSafe(int newX, int newY, vector<vector<bool>>& vis,  vector<vector<int>>& arr, int n){
+        
+        if((newX >= 0 && newX < n) && (newY >= 0 && newY < n) && vis[newX][newY] != 1 && arr [newX][newY] == 1) return true;
+        
+        return false;
+    }
+    
+    void solve(int x, int y, vector<vector<int>>& arr, int n, vector<string>& ans, vector<vector<bool>>& vis, string path){
+        
+        if(x == n-1 && y == n-1){
+            ans.push_back(path);
+            return;
+        }
+        
+        vis[x][y] = 1;
+        
+        if(isSafe(x+1, y, vis, arr, n)){
+            solve(x+1, y, arr, n, ans, vis, path + 'D');
+        }
+        
+        if(isSafe(x, y-1, vis, arr, n)){
+            solve(x, y-1, arr, n, ans, vis, path + 'L');
+
+        }
+        
+        if(isSafe(x, y+1, vis, arr, n)){
+            solve(x, y+1, arr, n, ans, vis, path + 'R');
+        }
+        
+        if(isSafe(x-1, y, vis, arr, n)){
+            solve(x-1, y, arr, n, ans, vis, path + 'U');
+        }
+        
+        vis[x][y] = 0;
+        
+    }
+    vector<string> findPath(vector<vector<int>> &mat) {
+        vector<string> ans;
+        vector<vector<bool>> visited(mat.size(), vector<bool>(mat.size(), 0));
+        
+        string path = "";
+        
+        solve(0, 0, mat, mat.size(), ans, visited, path);
+        
+        return ans;
+    }
+};