smallWorld.js

let [N, M] = gets().split(' ').map(Number);
let matrix = Array.from({ length: N }, () => gets().split('').map(Number));
let visited = Array.from({ length: N }, () => Array(M).fill(false));

let result = [];

// console.log(N, M, matrix, visited)

const dfs = (row, col) => {
    if(row < 0 || row >= N || col < 0 || col >= M || visited[row][col] || matrix[row][col] !== 1){
        return 0;
    }

    visited[row][col] = true;

    let size = 1;

    size += dfs(row - 1, col); // up
    size += dfs(row + 1, col); // down
    size += dfs(row, col - 1); // left
    size += dfs(row, col + 1); // right

    return size;
}

for(let i = 0; i < N; i++){
    for(let j = 0; j < M; j++){
        if(matrix[i][j] === 1 && !visited[i][j]){
            const size = dfs(i, j);
            result.push(size);
        }
    }
}
result.sort((a, b) => b - a);
for(let size of result){
    console.log(size)
}