Create number-of-paths-with-max-score.cpp

Author: kamyu104

C++/number-of-paths-with-max-score.cpp

@@ -0,0 +1,32 @@
+// Time:  O(n^2)
+// Space: O(n)
+
+class Solution {
+public:
+    vector<int> pathsWithMaxScore(vector<string>& board) {
+        static const int MOD = 1e9 + 7;
+        static const vector<pair<int, int>> directions{{1, 0}, {0, 1}, {1, 1}};
+        
+        vector<vector<vector<int>>> dp(2, vector<vector<int>>(board[0].size() + 1, vector<int>(2)));
+        dp[(board.size() - 1) % 2][board[0].size() - 1] = {0, 1};
+        for (int r = board.size() - 1; r >= 0; --r) {
+            for (int c = board[0].size() - 1; c >= 0; --c) {
+                if (board[r][c] == 'S' || board[r][c] == 'X') {
+                    continue;
+                }
+                dp[r % 2][c] = {0, 0};
+                for (const auto& [dr, dc] : directions) {
+                    if (dp[r % 2][c][0] < dp[(r + dr) % 2][c + dc][0]) {
+                        dp[r % 2][c] = dp[(r + dr) % 2][c + dc];
+                    } else if (dp[r % 2][c][0] == dp[(r + dr) % 2][c + dc][0]) {
+                        dp[r % 2][c][1] = (dp[r % 2][c][1]+dp[(r + dr) % 2][c + dc][1]) % MOD;
+                    }
+                }
+                if (dp[r % 2][c][1] && board[r][c] != 'E') {
+                    dp[r % 2][c][0] += board[r][c] - '0';
+                }
+            }
+        }
+        return dp[0][0];
+    }
+};