feat: solve problem 2257. Count Unguarded Cells in the Grid in C (#2210)

* test(problem-2257): add support to test in C

Signed-off-by: Alfi Maulana <alfi.maulana.f@gmail.com>

* feat(problem-2257/c): solve by using brute force approach

Signed-off-by: Alfi Maulana <alfi.maulana.f@gmail.com>

---------

Signed-off-by: Alfi Maulana <alfi.maulana.f@gmail.com>

README.md

@@ -462,7 +462,7 @@ LeetSpace serves as a dedicated workspace and archive for my [LeetCode](https://
 | [2232. Minimize Result by Adding Parentheses to Expression](https://leetcode.com/problems/minimize-result-by-adding-parentheses-to-expression/) | Medium | [C](./old-problems/2232/c/solution.c) [C++](./old-problems/2232/solution.cpp) |
 | [2235. Add Two Integers](https://leetcode.com/problems/add-two-integers) | Easy | [C](./old-problems/2235/c/solution.c) [C++](./old-problems/2235/solution.cpp) |
 | [2251. Number of Flowers in Full Bloom](https://leetcode.com/problems/number-of-flowers-in-full-bloom) | Hard | [C++](./problems/2251/solution.cpp) |
-| [2257. Count Unguarded Cells in the Grid](https://leetcode.com/problems/count-unguarded-cells-in-the-grid/) | Medium | [C++](./old-problems/2257/solution.cpp) |
+| [2257. Count Unguarded Cells in the Grid](https://leetcode.com/problems/count-unguarded-cells-in-the-grid/) | Medium | [C](./old-problems/2257/c/solution.c) [C++](./old-problems/2257/solution.cpp) |
 | [2264. Largest 3-Same-Digit Number in String](https://leetcode.com/problems/largest-3-same-digit-number-in-string/) | Easy | [C](./old-problems/2264/c/solution.c) [C++](./old-problems/2264/solution.cpp) |
 | [2275. Largest Combination With Bitwise AND Greater Than Zero](https://leetcode.com/problems/largest-combination-with-bitwise-and-greater-than-zero/) | Medium | [C](./old-problems/2275/c/solution.c) [C++](./old-problems/2275/solution.cpp) |
 | [2285. Maximum Total Importance of Roads](https://leetcode.com/problems/maximum-total-importance-of-roads/) | Medium | [C](./old-problems/2285/c/solution.c) [C++](./old-problems/2285/solution.cpp) |

old-problems/2257/CMakeLists.txt

@@ -1,2 +1,5 @@
+add_c_solution(c_solution c/interface.cpp c/solution.c)
+
 get_dir_name(id)
 add_problem_test(test-${id} test.yaml)
+target_link_libraries(test-${id} PRIVATE ${c_solution})

old-problems/2257/c/interface.cpp

@@ -0,0 +1,29 @@
+#include <vector>
+
+extern "C" {
+int countUnguarded(
+    int m, int n, int** guards, int guardsSize, int* guardsColSize,
+    int** walls, int wallsSize, int* wallsColSize);
+}
+
+int solution_c(
+    int m, int n, std::vector<std::vector<int>> guards,
+    std::vector<std::vector<int>> walls) {
+  std::vector<int*> guardsDatas(guards.size());
+  std::vector<int> guardsSizes(guards.size());
+  for (std::size_t i{0}; i < guards.size(); ++i) {
+    guardsDatas[i] = guards[i].data();
+    guardsSizes[i] = guards[i].size();
+  }
+
+  std::vector<int*> wallsDatas(walls.size());
+  std::vector<int> wallsSizes(walls.size());
+  for (std::size_t i{0}; i < walls.size(); ++i) {
+    wallsDatas[i] = walls[i].data();
+    wallsSizes[i] = walls[i].size();
+  }
+
+  return countUnguarded(
+      m, n, guardsDatas.data(), guardsDatas.size(), guardsSizes.data(),
+      wallsDatas.data(), wallsDatas.size(), wallsSizes.data());
+}

old-problems/2257/c/solution.c

@@ -0,0 +1,49 @@
+#include <stdlib.h>
+#include <string.h>
+
+int countUnguarded(
+    int m, int n, int** guards, int guardsSize, int* guardsColSize,
+    int** walls, int wallsSize, int* wallsColSize) {
+  (void)guardsColSize;
+  (void)wallsColSize;
+
+  char* cells = malloc(m * n * sizeof(char));
+  memset(cells, 0, m * n * sizeof(char));
+
+  for (int i = 0; i < guardsSize; ++i) {
+    cells[guards[i][0] * n + guards[i][1]] = 1;
+  }
+
+  for (int i = 0; i < wallsSize; ++i) {
+    cells[walls[i][0] * n + walls[i][1]] = 2;
+  }
+
+  for (int i = 0; i < guardsSize; ++i) {
+    for (int j = guards[i][0] + 1; j < m; ++j) {
+      if (cells[j * n + guards[i][1]] > 0) break;
+      cells[j * n + guards[i][1]] = -1;
+    }
+
+    for (int j = guards[i][0] - 1; j >= 0; --j) {
+      if (cells[j * n + guards[i][1]] > 0) break;
+      cells[j * n + guards[i][1]] = -1;
+    }
+
+    for (int j = guards[i][1] + 1; j < n; ++j) {
+      if (cells[guards[i][0] * n + j] > 0) break;
+      cells[guards[i][0] * n + j] = -1;
+    }
+
+    for (int j = guards[i][1] - 1; j >= 0; --j) {
+      if (cells[guards[i][0] * n + j] > 0) break;
+      cells[guards[i][0] * n + j] = -1;
+    }
+  }
+
+  int unguarded = 0;
+  for (int i = 0; i < m * n; ++i) {
+    if (cells[i] == 0) ++unguarded;
+  }
+
+  return unguarded;
+}

old-problems/2257/test.yaml

@@ -9,6 +9,7 @@ types:
   output: int
 
 solutions:
+  c:
   cpp:
     function: countUnguarded