Ruudukko

const rl = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout,
  terminal: false
});

let n;
let grid;
let counter = 0;

rl.on('line', line => {
  if (!n) {
    n = Number(line);
    grid = new Array(n);
    return;
  }

  grid[counter] = line;

  if (++counter === n) {
    rl.close();
  }
});

rl.on('close', () => {
  let ans = new Array(n);

  let c = 0;
  for (let i = 0; i < n; i++) {
    if (grid[0][i] === 'o') c++;
    ans[i] = [c];
  }

  for (let i = 1; i < n; i++) {
    let line = new Array(n);

    if (grid[i][0] === 'o') {
      line[0] = ans[0].map(val => val + 1);
    } else {
      line[0] = ans[0];
    }

    for (let j = 1; j < n; j++) {
      if (grid[i][j] === 'o') {
        line[j] = [...(new Set([
          ...line[j - 1].map(val => val + 1),
          ...ans[j].map(val => val + 1)
        ]))];
      } else {
        line[j] = [...(new Set([
          ...line[j - 1],
          ...ans[j]
        ]))];
      }
    }

    ans = line;
  }

  console.log(ans[n-1].length);
})

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 1, 2, 3

Verdict: ACCEPTED

Test 3

Group: 1, 2, 3

Verdict: ACCEPTED

Test 4

Group: 1, 2, 3

Verdict: ACCEPTED

Test 5

Group: 1, 2, 3

Verdict: ACCEPTED

Test 6

Group: 1, 2, 3

Verdict: ACCEPTED

Test 7

Group: 2, 3

Verdict: ACCEPTED

Test 8

Group: 2, 3

Verdict: ACCEPTED

Test 9

Group: 2, 3

Verdict: ACCEPTED

Test 10

Group: 2, 3

Verdict: ACCEPTED

Test 11

Group: 2, 3

Verdict: ACCEPTED

Test 12

Group: 2, 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 14

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 15

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 16

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 17

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 18

Group: 3

Verdict: TIME LIMIT EXCEEDED