CSP 2-7 Chessboard 棋盘

CSP-Training/2/7-chessboard.cpp

@@ -0,0 +1,72 @@
+//棋盘
+#include <cstdio>
+#include <cstring>
+#include <iostream>
+using namespace std;
+bool matrix[2000][2000];
+int main()
+{
+    int n, maxL, count[2001], i, j, k, l;
+    memset(count, 0, sizeof(count));
+    char temp;
+    scanf("%d", &n);
+    getchar();
+    for (int i = 0; i < n; i++)
+    {
+        for (int j = 0; j < n; j++)
+        {
+            temp = getchar();
+            matrix[i][j] = (bool)(temp - '0');
+        }
+        if (i != n - 1)
+        {
+            getchar();
+        }
+    }
+    for (i = 0; i < n; i++)
+    {
+        for (j = 0; j < n; j++) //枚举起始点
+        {
+            if (matrix[i][j] == 1) //黑点，可以作为起始点
+            {
+                maxL = (n - i) < (n - j) ? n - i : n - j; //最小离边距离作为最大边长
+                for (l = 1; l <= maxL; l++)               //枚举边长
+                {
+                    //下面其实只需要找新加进去的两边就行了
+                    for (k = j; k < j + l; k++) //下边，横坐标k，纵坐标i+l-1
+                    {
+                        if (matrix[i + l - 1][k] != (k - j + l) % 2)
+                        {
+                            break;
+                        }
+                    }
+                    if (k != j + l) //没检查完就break了，证明这个边长不合适，再大了当然也不合适了
+                    {
+                        break;
+                    }
+                    for (k = i; k < i + l; k++) //右边，横坐标j+l-1，横坐标k
+                    {
+                        if (matrix[k][j + l - 1] != (k - i + l) % 2)
+                        {
+                            break;
+                        }
+                    }
+                    if (k != i + l)
+                    {
+                        break;
+                    }
+                    count[l]++;
+                }
+            }
+        }
+    }
+    for (int i = n; i > 0; i--)
+    {
+        if (count[i] != 0)
+        {
+            printf("%d %d", i, count[i]);
+            break;
+        }
+    }
+    return 0;
+}