Merge pull request zapellass123#467 from rahullkr/main

Create longest increasing path in a matrix.cpp

Author: zapellass123

longest increasing path in a matrix.cpp

@@ -0,0 +1,33 @@
+class Solution {
+public:
+    int dp[201][201];
+   int dfs(vector<vector<int>> &mat, int i, int j, int pre) {
+        if (i < 0 || j < 0 || i == mat.size() || j == mat[0].size() || pre >= mat[i][j])
+            return 0;
+      if(dp[i][j])
+          return dp[i][j];
+       
+       if (dp[i][j])
+           return dp[i][j];
+       
+        int l = dfs(mat, i, j - 1, mat[i][j]);
+       
+        int r = dfs(mat, i, j + 1, mat[i][j]);
+       
+        int u = dfs(mat, i - 1, j, mat[i][j]);
+       
+        int d = dfs(mat, i + 1, j, mat[i][j]);
+       
+        return dp[i][j] = max({l, r, u, d}) + 1;
+    }
+    
+    int longestIncreasingPath(vector<vector<int>>& matrix) {
+        int res=0;
+        for(int i=0;i<matrix.size();i++){
+            for(int j=0;j<matrix[0].size();j++){
+                res=max(res,dfs(matrix, i, j,-2));
+            }
+        }
+        return res;
+    }
+};