DFS Island Counter - Advanced Visualizer

Grid State (5x5)

Code Execution

def numIslands(grid):
    count = 0
    rows = len(grid)
    cols = len(grid[0])
    for i in range(rows):
        for j in range(cols):
            if grid[i][j] == '1':  # Found island
                count += 1
                dfs(i, j)  # Mark entire island as visited
    return count
# --- DFS Helper Function ---
def dfs(row, col):
    if row < 0 or row >= rows or col < 0 or col >= cols or grid[row][col] == '0':
        return
    grid[row][col] = '0'  # Mark as visited
    dfs(row + 1, col)  # Down
    dfs(row - 1, col)  # Up
    dfs(row, col + 1)  # Right
    dfs(row, col - 1)  # Left