[백준] 블랙잭 - 2798

완전탐색 & 백트래킹 문제부터 풀어보고 있다.

const fs = require("fs");
const input = fs.readFileSync("./input.txt").toString().trim().split("\n");

const [N, M] = input[0].split(" ").map(Number);
const cards = input[1].split(" ").map(Number);

let max = 0;

const numbers = cards;
const selectedCount = 3;

const combinations = getCombinations(numbers, selectedCount);

for (const combination of combinations) {
  const sum = sumOfArray(combination);

  if (sum <= M) {
    max = Math.max(max, sum);
  }
}

console.log(max)

function getCombinations(arr, selectCount) {
  const result = [];

  function combinationsUtil(tempArr, start, selectedCount) {
    if (selectedCount === 3) {
      result.push([...tempArr]);
      return;
    }

    for (let i = start; i < arr.length; i++) {
      tempArr.push(arr[i]);
      combinationsUtil(tempArr, i + 1, selectedCount + 1);
      tempArr.pop();
    }
  }

  combinationsUtil([], 0, 0);

  return result;
}

function sumOfArray(arr) {
  return arr.reduce((acc, cur) => {
    return acc + cur;
  }, 0);
}