kuznetsov-m · December 12, 2022 06:45 · Dec 12, 2022 · Dec 11, 2022 · Dec 11, 2022
diff --git a/matrix_traversal_solution.cpp b/matrix_traversal_solution.cpp
@@ -18,7 +18,7 @@ vector<string> split(const string &);
  * The function accepts 2D_INTEGER_ARRAY mat as parameter.
  */
 
-void backtrack(vector<vector<int>> mat, int energy, int i, int j, int &maxi) {
+void backtrack(const vector<vector<int>> &mat, int energy, int i, int j, int &maxi) {
     energy -= mat[i][j];
 
     if (energy < maxi) {

diff --git a/matrix_traversal_solution.cpp b/matrix_traversal_solution.cpp
@@ -1,7 +1,7 @@
 #include <iostream>
 #include <vector>
 #include <string>
-#include <limits>
+#include <limits>       // <----- did not have time to fix here
 
 using namespace std;
 
@@ -38,7 +38,7 @@ void backtrack(vector<vector<int>> mat, int energy, int i, int j, int &maxi) {
 }
 
 int maxEnergy(vector<vector<int>> mat) {
-    int maxi = std::numeric_limits<int>::min();
+    int maxi = std::numeric_limits<int>::min();      // <----- did not have time to fix here
     for (auto j = 0; j < mat[0].size(); ++j) {
         auto energy = 100;
         backtrack(mat, energy, 0, j, maxi);

diff --git a/matrix_traversal_solution.cpp b/matrix_traversal_solution.cpp
@@ -0,0 +1,64 @@
+#include <iostream>
+#include <vector>
+#include <string>
+#include <limits>
+
+using namespace std;
+
+string ltrim(const string &);
+string rtrim(const string &);
+vector<string> split(const string &);
+
+
+
+/*
+ * Complete the 'maxEnergy' function below.
+ *
+ * The function is expected to return an INTEGER.
+ * The function accepts 2D_INTEGER_ARRAY mat as parameter.
+ */
+
+void backtrack(vector<vector<int>> mat, int energy, int i, int j, int &maxi) {
+    energy -= mat[i][j];
+
+    if (energy < maxi) {
+        return;
+    }
+    if (i == 3) {
+        maxi = std::max(energy, maxi);
+        return;
+    }
+
+    auto j_min = std::max(j - 1, 0);
+    auto j_max = std::min(j + 1, 3);
+
+    for (auto _j = j_min; _j <= j_max; ++_j) {
+        backtrack(mat, energy, i + 1, _j, maxi);
+    }
+}
+
+int maxEnergy(vector<vector<int>> mat) {
+    int maxi = std::numeric_limits<int>::min();
+    for (auto j = 0; j < mat[0].size(); ++j) {
+        auto energy = 100;
+        backtrack(mat, energy, 0, j, maxi);
+    }
+    return maxi;
+}
+
+int main()
+{
+    {
+        vector<vector<int>> mat = {
+            {99, 99, 0, 99},
+            {99, 99, 0, 99},
+            {99, 99, 0, 99},
+            {99, 199, 116, 199}
+        };
+
+        assert(maxEnergy(mat) == -16);
+    }
+
+    return 0;
+}
+