Create battleships-in-a-board.cpp

Author: kamyu104

C++/battleships-in-a-board.cpp

@@ -0,0 +1,21 @@
+// Time:  O(m * n)
+// Space: O(1)
+
+class Solution {
+public:
+    int countBattleships(vector<vector<char>>& board) {
+        if (board.empty() || board[0].empty()) {
+            return 0;
+        }
+
+        int cnt = 0;
+        for (int i = 0; i < board.size(); ++i) {
+            for (int j = 0; j < board[0].size(); ++j) {
+                cnt += board[i][j] == 'X' &&
+                       (i == 0 || board[i - 1][j] != 'X') &&
+                       (j == 0 || board[i][j - 1] != 'X');
+            }
+        }
+        return cnt;
+    }
+};