2024-08-11 Magic Squares In Grid

InSange/README.md

@@ -27,6 +27,7 @@
 | 23차시 | 2024.08.03 |  슬라이딩 윈도우  | [Minimum Swaps to Group All 1's Together 2](https://leetcode.com/problems/minimum-swaps-to-group-all-1s-together-ii/)  | [#23](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/82)]
 | 24차시 | 2024.08.04 |  BFS  | [트리](https://www.acmicpc.net/problem/1068)  | [#24](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/83)]
 | 25차시 | 2024.08.10 |  BFS  | [Minimum Height Trees](https://leetcode.com/problems/minimum-height-trees/)  | [#25](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/87)]
+| 26차시 | 2024.08.11 |  수학  | [Magic Squares In Grid](https://leetcode.com/problems/magic-squares-in-grid/)  | [#26](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/89)]
 ---
 
 https://leetcode.com/problems/robot-collisions/

InSange/수학/840_Magic Squares In Grid.cpp

@@ -0,0 +1,55 @@
+#include <vector>
+
+using namespace std;
+
+class Solution {
+public:
+    bool Check(int r, int c, vector<vector<int>>& grid)
+    {
+        vector<bool> isCheck(10, false);
+
+        for (int i = 0; i < 3; i++)
+        {
+            for (int j = 0; j < 3; j++)
+            {
+                int num = grid[r + i][c + j];
+                if (num < 1 || num > 9) return false;
+                if (isCheck[num]) return false;
+                isCheck[num] = true;
+            }
+        }
+
+        int standard_num = grid[r][c] + grid[r + 1][c + 1] + grid[r + 2][c + 2];
+        if (standard_num != grid[r][c + 2] + grid[r + 1][c + 1] + grid[r + 2][c]) return false;
+
+        for (int i = 0; i < 3; i++)
+        {
+            if (standard_num != (grid[r + i][c] + grid[r + i][c + 1] + grid[r + i][c + 2])) return false;
+        }
+
+        for (int i = 0; i < 3; i++)
+        {
+            if (standard_num != (grid[r][c + i] + grid[r + 1][c + i] + grid[r + 2][c + i])) return false;
+        }
+
+        return true;
+    }
+
+    int numMagicSquaresInside(vector<vector<int>>& grid) {
+        int col = grid[0].size(), row = grid.size();
+
+        if (col < 3 || row < 3) return 0;
+
+        int ans = 0;
+
+        for (int i = 0; i < row - 2; i++)
+        {
+            for (int j = 0; j < col - 2; j++)
+            {
+                if (Check(i, j, grid)) ans++;
+            }
+        }
+
+        return ans;
+    }
+};