Node.js)백준 17089번: 세 친구

https://www.acmicpc.net/problem/17089

17089번: 세 친구

const fs = require('fs');
const input = fs.readFileSync("./dev/stdin").toString().trim().split('\n');
const [N, M] = input[0].split(' ').map(Number)
const f = input.splice(1).map(v => v.split(' ').map(Number))
let answer = Infinity

const friends = Array.from(Array(N + 1), () => [])
f.forEach(v => {
  const [x, y] = v;
  friends[x].push(y)
  friends[y].push(x)
})

  for (let a = 1; a < friends.length; a++) {
    if (friends[a].length > 1) { // 친구가 한명인 놈은 계산할 가치가 없다.
      const A = a;
      const A_friends = friends[a];
      for (let b = 0; b < A_friends.length; b++) {
        const B = A_friends[b];
        const B_friends = friends[B]
        for (let c = 0; c < B_friends.length; c++) {
          if (B_friends[c] == A) continue;
          const C = B_friends[c];
          const C_friends = friends[C]
          if (C_friends.includes(A)) {
            const A_Sum = friends[A].filter(v => v != B && v != C).length;
            const B_Sum = friends[B].filter(v => v != A && v != C).length;
            const C_Sum = friends[C].filter(v => v != B && v != A).length;
            const total_sum = A_Sum + B_Sum + C_Sum;
            if (total_sum < answer) {
              answer = total_sum;
            }
          }

        }
      }
    }
  }
  if(answer==Infinity){
    console.log(-1)
  }else{
    console.log(answer)
  }