Ruudukko

const { readSync,readFileSync } = require('fs');
const { Buffer } = require('buffer');


function readline() {
  let buf = Buffer.alloc(1000, 10);
  for(i=0; i<1000; i++) {
    if(!readSync(0, buf, i, 1) || buf[i]===10) {
      return buf.toString("utf8").split("\n")[0];
    }
  }
}

const mod = 1e9+7;
const n = Number(readline());

//let buf = Buffer.alloc((String(n**2).length+1)*(n**2), 10);
//console.log(readSync(0, buf,0,200000));
//const table = buf.toString("utf8").split("\n").filter(e=>e).map(e=>e.split(" ")).flat(1).map(e=>parseInt(e));
const tablestr = readFileSync(0,{encoding:"utf8"});
let table = [];

let itemstr = "";
for(let i=0; i<tablestr.length; i++) {
  switch (tablestr[i]) {
    case " ":
    case "\n":
      itemstr&&table.push(parseInt(itemstr));
      itemstr="";
      break;
    default:
      itemstr+=tablestr[i];
  }
}

let paths = Array(n**2).fill(0);
let nummap = Array(n**2+10).fill();
//const nummap = Array(n**2+10).fill().map(()=>[]);

//console.log(table.length);

table.forEach((e,i)=>nummap[e]?nummap[e].push(i):nummap[e]=[i]);
//table.forEach((e,i)=>nummap[e].push(i));

let newpaths = [];

nummap.forEach((e,i)=>{
//  if(!(i%1000)) console.log(i);
  if(e) {
    newpaths = [];
    e.forEach(x=>{
      let sum = 1;
      let a=x-x%n, b=x%n;
      for(let y=0;y<n;y++) {
        sum+=paths[a+y];
        sum+=paths[b+y*n];
      }
      newpaths.push([x,sum%mod]);
    })
    newpaths.forEach(e=>paths[e[0]]=e[1]);
//    console.log(paths);
  }
});

console.log((paths.reduce((v,e)=>(v+e)%mod,0)%mod).toString());

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: 2, 3

Verdict: ACCEPTED

Test 5

Group: 2, 3

Verdict: ACCEPTED

Test 6

Group: 2, 3

Verdict: ACCEPTED

Test 7

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 8

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 9

Group: 3

Verdict: TIME LIMIT EXCEEDED