AlgoMotion
Quiz25
Graph BFS / DFS/Medium

Number of IslandsPRO PASS

Time: O(M * N)Space: O(M * N)

Step 1: Setup & Initialization - Number of Islands

Flood-fill DFS/BFS to sink land cells.

Array Elements & Pointers
10
[0]
20
[1]
30
[2]
40
[3]
50
[4]
Live Variables & Invariants
status:Initialized
pattern:Number of Islands
Step 1 / 333%
Solution Code
1
function numIslands(grid: string[][]): number {
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  let count = 0;
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  for (let r = 0; r < grid.length; r++) {
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    for (let c = 0; c < grid[0].length; c++) {
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      if (grid[r][c] === '1') { count++; dfs(grid, r, c); }
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    }
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  }
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  return count;
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}

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