Ruudukko

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

let n;
let grid;
let input;

let c = 0;
rl.on('line', line => {
  if (!n) {
    n = Number(line);
    input = new Array(n);
    grid = new Array(n);
    for (let i = 0; i < n; i++) grid[i] = new Array(n).fill(0);
    return;
  }

  input[c] = line;

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

    for (let i = 1; i < n; i++) {
      grid[i][0] = [grid[i-1][0][0] + (input[i][0] === 'o'
        ? 1
        : 0)];
    }

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