number of islands without space
#include <bits/stdc++.h>
using namespace std;
#define ROW 5
#define COL 5
int isSafe(int M[][COL], int row, int col)
{
return (row >= 0) && (row < ROW) && (col >= 0) && (col < COL) && (M[row][col] && M[row][col] != -1);
}
void DFS(int M[][COL], int row, int col )
{
static int rowNbr[] = { -1, -1, -1, 0, 0, 1, 1, 1 };
static int colNbr[] = { -1, 0, 1, -1, 1, -1, 0, 1 };
M[row][col] = -1;
for (int k = 0; k < 8; ++k)
if (isSafe(M, row + rowNbr[k], col + colNbr[k]))
{
DFS(M, row + rowNbr[k], col + colNbr[k]);
}
}
int countIslands(int M[][COL])
{
int count = 0;
for (int i = 0; i < ROW; ++i)
for (int j = 0; j < COL; ++j)
if (M[i][j] && M[i][j] != -1)
{
DFS(M, i, j);
++count;
}
return count;
}
int main()
{
int M[][COL] = {
{ 1, 1, 0, 0, 0 },
{ 0, 1, 0, 0, 1 },
{ 1, 0, 0, 1, 1 },
{ 0, 0, 0, 0, 0 },
{ 1, 0, 1, 0, 1 }
};
cout << "Number of islands is: " << countIslands(M);
return 0;
}