호박고구마

def solution(my_string):
    alpa = []

    for i in range(65, 91):
        alpa.append(chr(i))
    for i in range(97,123):
        alpa.append(chr(i))
    # alpa : [A,B,C,D, ....Z, a, b, c, d, ...., z]
    
    result = []
    for item in alpa:
        result.append(my_string.count(item))
    return result

https://school.programmers.co.kr/learn/courses/30/lessons/181902

설명

A~Z, a~z까지 alpa라는 리스트에 추가를 먼저했다.

그리고 alpa리스트안에 알파벳을 각 순회하면서 count함수를 사용해서 result라는 함수에 추가했다.

function main() {
  const filePath = process.platform === "linux" ? "/dev/stdin" : "ex.txt";
  const [n, inputs, v] = require("fs")
    .readFileSync(filePath)
    .toString()
    .trim()
    .split("\n");
  console.log(inputs.split(" ").filter((item) => item === v).length);
}

main();

https://www.acmicpc.net/problem/10814

const filePath = process.platform === "linux" ? "/dev/stdin" : "ex.txt";
const [n, ...lines] = require("fs")
  .readFileSync(filePath)
  .toString()
  .trim()
  .split("\n");

let users = [];

lines.forEach((line, index) => {
  const [age, name] = line.split(" ");
  users.push({ age: parseInt(age), name, index });
});

users.sort((a, b) => a.age - b.age);

users.forEach(({ age, name }) => {
  console.log(`${age} ${name}`);
});

https://www.acmicpc.net/problem/1427

function main() {
  const filePath = process.platform === "linux" ? "/dev/stdin" : "ex.txt";
  const input = require("fs").readFileSync(filePath).toString().trim();
  const result = [...input]
    .map((num) => parseInt(num))
    .sort((a, b) => b - a)
    .join("");
  console.log(result);
}

main();

function calculateConstruct(value) {
  return [...value.toString()]
    .map((item) => parseInt(item))
    .reduce((acc, cur) => acc + cur, parseInt(value));
}

function main() {
  const filePath = process.platform === "linux" ? "/dev/stdin" : "ex.txt";
  const N = require("fs").readFileSync(filePath).toString().trim();

  let result = 0;
  for (let i = 0; i < N; i++) {
    const construct = calculateConstruct(i);
    if (construct === parseInt(N)) {
      result = i;
      break;
    }
  }
  console.log(result);
}

main();

const filePath = process.platform === "linux" ? "/dev/stdin" : "ex.txt";
const [firstLine, ...lines] = require("fs")
  .readFileSync(filePath)
  .toString()
  .trim()
  .split("\n");

const [N, M] = firstLine.split(" ").map((item) => parseInt(item));
let packages = [];
let pieces = [];

lines.forEach((line) => {
  const package = parseInt(line.split(" ")[0]);
  const piece = parseInt(line.split(" ")[1]);
  packages.push(package);
  pieces.push(piece);
});

packages.sort((a, b) => a - b);
pieces.sort((a, b) => a - b);

const packageCount = parseInt(N / 6);
const pieceCount = parseInt(N % 6);

const cheapPackage = packages[0];
const cheapPieces = pieces[0];

const minPrices = [
  cheapPieces * N,
  packageCount * cheapPackage + pieceCount * cheapPieces,
  (packageCount + 1) * cheapPackage,
];

minPrices.sort((a, b) => a - b);
console.log(minPrices[0]);​

const items = require("fs")
  .readFileSync("/dev/stdin")
  .toString()
  .trim()
  .split("\n")
  .map((item) => parseInt(item));

const total = items.reduce((acc, cur) => acc + cur, 0);
let result = [];
for (let i = 0; i < items.length; i++) {
  for (let j = i + 1; j < items.length; j++) {
    if (total - (items[i] + items[j]) === 100) {
      result = items.filter((item) => items[i] !== item && item !== items[j]);
    }
  }
}
result.sort((a, b) => a - b);
result.forEach((item) => console.log(item));

function calcTotalPrice(price, count) {
  let result = 0;
  for (let i = 1; i <= count; i++) {
    result += price * i;
  }
  return result;
}

function solution(price, money, count) {
  const totalPrice = calcTotalPrice(price, count);
  return totalPrice - money > 0 ? totalPrice - money : 0;
}