计算每个岛按行和按列分隔的岛数

给定一个只有两个可能值“X”和“O”的矩形矩阵。值“X”总是以矩形岛的形式出现，并且这些岛总是按行和按列由至少一行“O”隔开。请注意，岛屿只能对角相邻。计算给定矩阵中岛屿的数量。
例子：

mat[M][N] =  {{'O', 'O', 'O'},
              {'X', 'X', 'O'},
              {'X', 'X', 'O'},
              {'O', 'O', 'X'},
              {'O', 'O', 'X'},
              {'X', 'X', 'O'}
             };
Output: Number of islands is 3

mat[M][N] =  {{'X', 'O', 'O', 'O', 'O', 'O'},
              {'X', 'O', 'X', 'X', 'X', 'X'},
              {'O', 'O', 'O', 'O', 'O', 'O'},
              {'X', 'X', 'X', 'O', 'X', 'X'},
              {'X', 'X', 'X', 'O', 'X', 'X'},
              {'O', 'O', 'O', 'O', 'X', 'X'},
             };
Output: Number of islands is 4

我们强烈建议您最小化您的浏览器并首先自己尝试。
这个想法是计算给定矩阵的所有左上角。我们可以通过检查以下条件来检查“X”是否在左上角。
1) 如果正上方的单元格是“O”，则“X”是矩形的顶部
2）如果左边的单元格是“O”，则“X”是矩形的最左边
请注意，我们必须检查这两种情况，因为矩形岛中可能有多个顶部单元格和多个最左侧单元格。下面是上述想法的实现。

C++

// A C++ program to count the number of rectangular
// islands where every island is separated by a line
#include
using namespace std;
 
// Size of given matrix is M X N
#define M 6
#define N 3
 
// This function takes a matrix of 'X' and 'O'
// and returns the number of rectangular islands
// of 'X' where no two islands are row-wise or
// column-wise adjacent, the islands may be diagonally
// adjacent
int countIslands(int mat[][N])
{
    int count = 0; // Initialize result
 
    // Traverse the input matrix
    for (int i=0; i

---

Java

// A Java program to count the number of rectangular
// islands where every island is separated by a line
import java.io.*;
 
class islands
{
    // This function takes a matrix of 'X' and 'O'
    // and returns the number of rectangular islands
    // of 'X' where no two islands are row-wise or
    // column-wise adjacent, the islands may be diagonally
    // adjacent
    static int countIslands(int mat[][], int m, int n)
    {
        // Initialize result
        int count = 0;
 
        // Traverse the input matrix
        for (int i=0; i

---

Python3

# A Python3 program to count the number
# of rectangular islands where every
# island is separated by a line
 
# Size of given matrix is M X N
M = 6
N = 3
 
# This function takes a matrix of 'X' and 'O'
# and returns the number of rectangular
# islands of 'X' where no two islands are
# row-wise or column-wise adjacent, the islands
# may be diagonally adjacent
def countIslands(mat):
 
    count = 0; # Initialize result
 
    # Traverse the input matrix
    for i in range (0, M):
     
        for j in range(0, N):
         
            # If current cell is 'X', then check
            # whether this is top-leftmost of a
            # rectangle. If yes, then increment count
            if (mat[i][j] == 'X'):
             
                if ((i == 0 or mat[i - 1][j] == 'O') and
                    (j == 0 or mat[i][j - 1] == 'O')):
                    count = count + 1
             
    return count
 
# Driver Code
mat = [['O', 'O', 'O'],
       ['X', 'X', 'O'],
       ['X', 'X', 'O'],
       ['O', 'O', 'X'],
       ['O', 'O', 'X'],
       ['X', 'X', 'O']]
                 
print("Number of rectangular islands is",
                       countIslands(mat))
 
# This code is contributed by iAyushRaj

C#

// A C# program to count the number of rectangular
// islands where every island is separated by
// a line
using System;
 
class GFG {
     
    // This function takes a matrix of 'X' and 'O'
    // and returns the number of rectangular
    // islands of 'X' where no two islands are
    // row-wise or column-wise adjacent, the
    // islands may be diagonally adjacent
    static int countIslands(int [,]mat, int m, int n)
    {
         
        // Initialize result
        int count = 0;
 
        // Traverse the input matrix
        for (int i = 0; i < m; i++)
        {
            for (int j = 0; j < n; j++)
            {
                // If current cell is 'X', then check
                // whether this is top-leftmost of a
                // rectangle. If yes, then increment
                // count
                if (mat[i,j] == 'X')
                {
                    if ((i == 0 || mat[i-1,j] == 'O') &&
                        (j == 0 || mat[i,j-1] == 'O'))
                        count++;
                }
            }
        }
 
        return count;
    }
     
    // Driver program
    public static void Main ()
    {
         
        // Size of given matrix is m X n
        int m = 6;
        int n = 3;
        int [,]mat = { {'O', 'O', 'O'},
                       {'X', 'X', 'O'},
                       {'X', 'X', 'O'},
                       {'O', 'O', 'X'},
                       {'O', 'O', 'X'},
                       {'X', 'X', 'O'}
                    };
        Console.WriteLine("Number of rectangular "
         + "islands is: " + countIslands(mat, m, n));
    }
}
 
// This code is contributed by Sam007.

Javascript

    // A Javascript program to count the number of rectangular
    // islands where every island is separated by a line
     
    // This function takes a matrix of 'X' and 'O'
    // and returns the number of rectangular islands
    // of 'X' where no two islands are row-wise or
    // column-wise adjacent, the islands may be diagonally
    // adjacent
    function countIslands(mat, m, n)
    {
        // Initialize result
        let count = 0;
   
        // Traverse the input matrix
        for (let i = 0; i < m; i++)
        {
            for (let j = 0; j < n; j++)
            {
                // If current cell is 'X', then check
                // whether this is top-leftmost of a
                // rectangle. If yes, then increment count
                if (mat[i][j] == 'X')
                {
                    if ((i == 0 || mat[i-1][j] == 'O') &&
                        (j == 0 || mat[i][j-1] == 'O'))
                        count++;
                }
            }
        }
   
        return count;
    }
     
    // Size of given matrix is m X n
    let m = 6;
    let n = 3;
    let mat = [['O', 'O', 'O'],
                ['X', 'X', 'O'],
                ['X', 'X', 'O'],
                ['O', 'O', 'X'],
                ['O', 'O', 'X'],
                ['X', 'X', 'O']
              ];
    document.write("Number of rectangular islands is "
                       + countIslands(mat, m, n));
 
// This code is contributed by suresh07.

输出：


Number of rectangular islands is 3