Create Rat_in_a_Maze.cpp

Author: Smruti2002

Backtracking/Rat_in_a_Maze.cpp

@@ -0,0 +1,77 @@
+// https://practice.geeksforgeeks.org/problems/rat-in-a-maze-problem/1
+
+#include <bits/stdc++.h>
+using namespace std;
+
+class Solution{
+    public:
+    
+    vector <string> v;
+    bool check (int x, int y, int n, vector<vector<int>> &m, char ch)
+    {
+        if(ch=='U')
+            x--;
+        else if(ch=='D')
+            x++;
+        else if(ch=='R')
+            y++;
+        else
+            y--;
+            
+        if(x<n && y<n && x>=0 && y>=0 && m[x][y]==1)
+            return true;
+        return false;
+    }
+    
+    void rec(vector<vector<int>> &m,int n,int x,int y,string s)
+    {
+        string temp = s;
+        if(x==n-1 && y==n-1)
+                {v.push_back(s);return ;}
+        if(check(x,y,n,m,'U')==false && check(x,y,n,m,'D')==false && check(x,y,n,m,'R')==false && check(x,y,n,m,'L')==false)    
+        {
+            return;
+        }
+        if(check(x,y,n,m,'U'))
+        {
+            s = s+'U';
+            m[x-1][y] = 0;
+            rec(m,n,x-1,y,s);
+            m[x-1][y] = 1;
+            s = temp;
+        }
+        if(check(x,y,n,m,'D'))
+        {
+            s = s+'D';
+            m[x+1][y] = 0;
+            rec(m,n,x+1,y,s);
+            m[x+1][y] = 1;
+            s = temp;
+        }
+        if(check(x,y,n,m,'R'))
+        {
+            s = s+'R';
+            m[x][y+1] = 0;
+            rec(m,n,x,y+1,s);
+            m[x][y+1] = 1;
+            s = temp;
+        }
+        if(check(x,y,n,m,'L'))
+        {
+            s = s+'L';
+            m[x][y-1] = 0;
+            rec(m,n,x,y-1,s);
+            m[x][y-1] = 1;
+            s = temp;
+        }
+    }
+    
+    vector<string> findPath(vector<vector<int>> &m, int n) {
+        
+        if(m[0][0]==0)
+            return v;
+        m[0][0] = 0;
+        rec(m,n,0,0,"");
+        return v;
+    }
+};