This approach involves iterating over every cell in the grid. For each land cell (grid[i][j] == 1), we assume it initially contributes 4 to the perimeter. We then check its neighboring cells (up, down, left, right). If a neighboring cell is also land, we reduce the perimeter by one for each connection to another land cell, since that edge does not contribute to the perimeter.

This approach leverages Depth-First Search to traverse the land cells. Starting from any land cell, we recursively visit all connected land cells and calculate the perimeter contribution for each by checking the edges. If an edge points to water or out of bounds, it contributes to the perimeter.