Added Rotting Oranges Problem Solution

leetcode/Rotting_Oranges.cpp

@@ -0,0 +1,59 @@
+class Solution {
+public:
+    int orangesRotting(vector<vector<int>>& grid) {
+
+        int n=grid.size();
+        int m=grid[0].size();
+
+        int vis[n][m];
+        queue < pair< pair< int,int >,int > > q;
+        int fresh=0;
+        for(int i=0;i<n;i++)
+        {
+            for(int j=0;j<m;j++)
+            {
+                if(grid[i][j]==2)
+                {
+                    q.push({{i,j},0});
+                    vis[i][j]=2;
+                }
+                else{
+                    vis[i][j]=0;
+                }
+                if(grid[i][j]==1)
+                    fresh++;
+            }
+        }
+
+        int tm=0;
+
+        int cnt=0;
+        while(!q.empty())
+        {
+             int delrow[]={1,0,-1,0};
+        int delcol[]={0,-1,0,1};
+        int r=q.front().first.first;
+        int c=q.front().first.second;
+        int t=q.front().second;
+            tm=max(tm,t);
+        q.pop();
+
+        for(int i=0;i<4;i++)
+        {
+                int nrow=r+delrow[i];
+                int ncol=c+delcol[i];
+            if(nrow>=0 && nrow<n && ncol>=0 && ncol<m && grid[nrow][ncol]==1 && vis[nrow][ncol]!=2)
+            {
+                q.push({{nrow,ncol},t+1});
+                vis[nrow][ncol]=2;
+                cnt++;
+
+            }
+        }
+        }
+
+              if(cnt != fresh) return -1;
+
+        return tm;
+    }
+};