기본 수학 2

const fs = require("fs");
const input = fs.readFileSync("./input.txt").toString().trim().split('\n');
const inputNums = input[1].trim().split(' ').map(Number);
let count = 0;
let primeNum = 0;

for (let i = 0; i < parseInt(input[0]); i++) {
    count = 0;
    for (let j = 1; j <= inputNums[i]; j++) {
        if (inputNums[i]%j == 0) {
            count++;
        }
    }
    if (count == 2) {
        primeNum++;
    }
}

console.log(primeNum);

const fs = require("fs");
const input = fs.readFileSync("./input.txt").toString().trim().split('\n');
const min = parseInt(input[0]);
const max = parseInt(input[1]);
let count = 0;
let primeArr = [];

for (let i = min; i <= max; i++) {
    count = 0;
    for (let j = 1; j <= i; j++) {
        if (i%j == 0) {
            count++;
        }
        if (count > 2) {
            break;
        }
    }
    if (count == 2) {
        primeArr.push(i);
    }
}

const primeSum = primeArr.reduce((prev, cur) => prev + cur, 0);
const primeMin = Math.min(...primeArr);

if (primeArr.length == 0) {
    console.log(-1);
} else {
    console.log(primeSum);
    console.log(primeMin);
}

const fs = require("fs");
const input = fs.readFileSync("./input.txt").toString().trim();
let inputNum = parseInt(input);
let factoArr = [];
let count = 2;
let primeCount = 0;
let isItPrime = false;

while (!isItPrime) {
    if (inputNum == 1) {
        break;
    }

    primeCount = 0;
    for (let i = 1; i <= inputNum; i++) {
        if (inputNum % i == 0) {
            primeCount++;
        }
        if (primeCount > 2) {
            break;
        }
    }
    
    if (primeCount == 2) {
        factoArr.push(inputNum);
        isItPrime = true;
        break;
    }

    if (inputNum % count == 0) {
        factoArr.push(count);
        inputNum = inputNum / count;
        count = 1;
    }
    count++;
}

factoArr.sort(function(a, b)  {
  return a - b;
});

if (inputNum != 1) {
    for (let i = 0; i < factoArr.length; i++) {
        console.log(factoArr[i]);
    }
}

const fs = require("fs");
const input = fs.readFileSync("./input.txt").toString().trim().split(" ");
const min = parseInt(input[0]);
const max = parseInt(input[1]);
let isPrimeArr = new Array(max + 1);

isPrimeArr.fill(true);
isPrimeArr[0] = false;
isPrimeArr[1] = false;

for (let i = 2; i <= max; i++) {
  if (isPrimeArr[i]) {
    for (let j = i + i; j <= max; j += i) {
      isPrimeArr[j] = false;
    }
  }
}

for (let i = min; i <= max; i++) {
  if (isPrimeArr[i]) {
    console.log(i);
  }
}

const fs = require("fs");
const input = fs.readFileSync("./input.txt").toString().trim().split("\n");
let count = 0;

for (let k = 0; k < input.length-1; k++) {
  let n = parseInt(input[k]);
  let isPrimeArr = new Array(2 * n + 1);
  isPrimeArr.fill(true);
  isPrimeArr[0] = false;
  isPrimeArr[1] = false;
  for (let i = 2; i <= 2*n; i++) {
    if (isPrimeArr[i]) {
      for (let j = i + i; j <= 2*n; j += i) {
        isPrimeArr[j] = false;
      }
    }
  }
  isPrimeArr = isPrimeArr.slice(n+1, 2*n+1)
  count = isPrimeArr.reduce((cnt, element) => cnt + (true === element), 0);
  console.log(count);
}

const fs = require("fs");
const input = fs.readFileSync("./input.txt").toString().trim().split("\n");
let n = 0;
let primeNums = [];
let partition = [];

for (let k = 1; k < input.length; k++) { // 모든 케이스에 대하여 (1번째 for문)
  partition = [];
  primeNums = [];
  n = parseInt(input[k]);
  let isPrimeArr = new Array(n + 1);
  isPrimeArr.fill(true);
  isPrimeArr[0] = false;
  isPrimeArr[1] = false;
  for (let i = 2; i <= n; i++) { // 2번째 for문
    if (isPrimeArr[i]) {
      for (let j = i + i; j <= n; j += i) { // 3번째 for문
        isPrimeArr[j] = false;
      }
    }
  }
  for (let i = 0; i < isPrimeArr.length; i++) { // 4번째 for문
    if(isPrimeArr[i]) {
      primeNums.push(i); // 우선 1929번과 같은 알고리즘으로 소수를 구하여 배열에 push
    }
  }
  for (let i = 0; i < primeNums.length; i++) { // 5번째 for문
    if (primeNums.includes(n-primeNums[i])) {
      partition.push([n-primeNums[i], primeNums[i], n-primeNums[i]*2]);
    }
  }
	while (partition[i][2] > 0) { // while문
    partition.shift();
  }
  console.log(partition[0][0] + ' ' + partition[0][1]);
}