Ruudukko

const readLine = require('readline')
 
const read = readLine.createInterface({
    input: process.stdin,
    output: process.stdout,
    terminal: false
});
 
read.on('line', n => {   
    let grid = [[]]
    let row = []
 
    for(let i = 0; i < n; i++) grid[0][i] = i + 1
 
    for(let a = 1; a < n; a++) {
        row.push(grid.length + 1)
        for(let b = 1; b < n; b++) {
            let num = 0
            while(true) {
                num++
                let doesFit = true
                for(let c = 0; c < grid.length; c++) {
                    if(grid[c][row.length] == num) doesFit = false
                }
                if(!doesFit) continue
                if(!row.includes(num)) break
            }
            row.push(num)
        }
        grid.push(row)
        row = []
    }
 
    for(let i = 0; i < grid.length; i++) {
        console.log(grid[i].join(' '))
    }
})

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED