Node.js)백준 1182: 부분수열의 합

https://www.acmicpc.net/problem/1182

1182번: 부분수열의 합

const fs = require('fs');
const input = fs.readFileSync("./dev/stdin").toString().trim().split("\n").map(v=>v.split(' ').map(x=>+x));
const [N,S] = input[0];
const nums = input[1];

let answer=0;
for(let i = 1; i<1<<N; i++ ){
  let now = i;
  let sum = 0;
  for(let j = 0; j<N; j++){
    if((now&1)==1) sum+=nums[j]
    now = now>>1;
  }
  if(sum==S){
    answer++;
  }
}

console.log(answer)