function solution(n) {
function isPrime(num) {
if (num === 1) return false;
for (let i = 2; i < num; i++) {
if (num % i === 0) return false;
}
return true;
}
let count = 0;
for (let i = 2; i <= n; i++) {
if (isPrime(i)) count++
}
return count;
}
function solution(n) {
let count = 0;
function isPrime(num) {
if (num === 1) return false;
for (let i = 2; i <= num / 2; i++) {
if (num % i === 0) return false;
}
return true;
}
for (let i = 2; i <= n; i++) {
if (isPrime(i)) count++;
}
return count;
}
function solution(n) {
let count = 0;
function isPrime(num) {
if (num === 1) return false;
for (let i = 2; i * i <= num; i++) {
if (num % i === 0) return false;
}
return true;
}
for (let i = 2; i <= n; i++) {
if (isPrime(i)) count++;
}
return count;
}
function solution(n) {
let count = 1;
function isPrime(num) {
if (num === 2) {
return true;
} else if (num % 2 === 0) {
return false;
}
for (let i = 3; i * i <= num; i += 2) {
if (num % i === 0) return false;
}
return true;
}
for (let i = 3; i <= n; i += 2) {
if (isPrime(i)) count++;
}
return count;
}
function solution(n) {
const s = new Set();
for(let i=1; i<=n; i+=2){
s.add(i);
}
s.delete(1);
s.add(2);
for(let j=3; j<Math.sqrt(n); j++){
if(s.has(j)){
for(let k=j*2; k<=n; k+=j){
s.delete(k);
}
}
}
return s.size;
}