From 63eaa0fadf3867c187471c51c77699f12ad0ea51 Mon Sep 17 00:00:00 2001
From: Divyanshu Sharma <21bcs079@iiitdmj.ac.in>
Date: Thu, 1 Jun 2023 22:48:34 +0530
Subject: [PATCH] I have added Solution of leetcode Problem 1091

---
 .../1091- Shortest_Path_in_Binary_Matrix.cpp  | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 LeetCode/1091- Shortest_Path_in_Binary_Matrix.cpp

diff --git a/LeetCode/1091- Shortest_Path_in_Binary_Matrix.cpp b/LeetCode/1091- Shortest_Path_in_Binary_Matrix.cpp
new file mode 100644
index 00000000..6487e6c1
--- /dev/null
+++ b/LeetCode/1091- Shortest_Path_in_Binary_Matrix.cpp	
@@ -0,0 +1,36 @@
+// This is solution of Leetcode Problem : 1091. Shortest Path in Binary Matrix
+// https://leetcode.com/problems/shortest-path-in-binary-matrix/description/
+// I have used BFS traversal approach here 
+// Time and Space Complexity both are O(n^2) here
+
+class Solution {
+public:
+    int shortestPathBinaryMatrix(vector<vector<int>>& grid) {
+        int n = grid.size();
+        if(grid[0][0]) return -1;
+        queue<pair<int , int>> q;
+        vector<vector<bool>>seen(n , vector<bool>(n,false ));
+        seen[0][0] = true;
+        q.push({0 , 0});
+       
+        while(!q.empty()){
+            auto a=q.front(); q.pop();
+            int i=a.first , j=a.second;
+            if(i==n-1 && j==n-1){
+                return grid[i][j] + 1;
+            }
+            int I[] = {0 , 0 , 1 , 1 , 1, -1 , -1 , -1};
+            int J[] = {1 , -1, 0 , -1, 1 , 0 , -1 , 1 };
+            for(int p=0 ; p<8 ; p++){
+                int x = i + I[p];
+                int y = j + J[p];
+                if(x>=0 && x<n && y>=0 && y<n && grid[x][y]==0 && !seen[x][y]){
+                grid[x][y] =1+grid[i][j]; 
+                seen[x][y] = true;
+                q.push({x, y});
+                }
+            }
+        }
+        return -1;
+    }
+};
\ No newline at end of file