From b6331f6edd1f93852a1e7e6ddc6416dd894880f5 Mon Sep 17 00:00:00 2001
From: Fazeel Usmani <fazeelusmani18@gmail.com>
Date: Fri, 29 Oct 2021 22:11:44 +0530
Subject: [PATCH] Create 29_rottingOranges.cpp

---
 .../29_rottingOranges.cpp                     | 58 +++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 10 October LeetCode Challenge 2021/29_rottingOranges.cpp

diff --git a/10 October LeetCode Challenge 2021/29_rottingOranges.cpp b/10 October LeetCode Challenge 2021/29_rottingOranges.cpp
new file mode 100644
index 0000000..f7b262c
--- /dev/null
+++ b/10 October LeetCode Challenge 2021/29_rottingOranges.cpp	
@@ -0,0 +1,58 @@
+class Solution {
+public:
+    int orangesRotting(vector<vector<int>>& grid) {
+        
+        if (grid.empty() || grid[0].empty())
+            return 0;
+        
+        int H = grid.size();
+        int W = grid[0].size();
+        
+        auto inside = [&](int row, int col){
+            return 0<=row && row<H && 0<=col && col<W;
+        };
+        
+        queue<pair<int, int> > q;
+                    
+        for (int i = 0; i < H; ++i){
+            for (int j = 0; j < W; ++j){
+                if (grid[i][j] == 2){
+                    q.push({i, j});
+                }
+            }
+        }
+                
+        vector<pair<int, int> > directions { {-1,0}, {0,-1}, {1,0}, {0,1} };
+        int minutes = 0;
+        
+        while (!q.empty()){
+            
+            int sz = q.size();
+            bool flag = false;
+            for (int k=0; k<sz; ++k){
+                pair<int, int> orange = q.front();
+                q.pop();
+                int i = orange.first, j = orange.second;
+                  
+                for (pair<int, int> dir: directions){
+                    int newRow = i + dir.first;
+                    int newCol = j + dir.second;
+                    if (inside(newRow,newCol) && grid[newRow][newCol] == 1){                  
+                        flag = true;
+                        q.push({newRow, newCol});                        
+                        grid[newRow][newCol] = 2;
+                    }
+                }                
+            }            
+            if (flag)
+                minutes++;            
+        }
+        
+        for(auto rows : grid)
+            for(auto val : rows)
+                if(val == 1)
+                    return -1;        
+        
+        return minutes;
+    }
+};