약수의 개수와 덧셈

https://programmers.co.kr/learn/courses/30/lessons/77884

코딩테스트 연습 - 약수의 개수와 덧셈

def solution(left, right):
    answer = 0
    for each in range(left, right + 1):
        if count_divisor(each):
            answer += each
        else:
            answer -= each
    return answer


def count_divisor(number):
    count = 0
    for each in range(1, number + 1):
        if number % each == 0:
            count += 1
    return count % 2 == 0

약수의 개수가 홀수인 수는 제곱근이 정수인 수입니다.

2: 1, 2
4: 1, '2', 4
8: 1, 2, 4, 8
16: 1, 2, '4', 8, 16

def solution(left, right):
    answer = 0
    for each in range(left, right + 1):
        if (temp := each ** 0.5) - int(temp) > 0:
            answer += each
        else:
            answer -= each
    return answer

def solution(left, right):
    return sum(each if (temp := each ** 0.5) - int(temp) > 0 else - each for each in range(left, right + 1))

PEP위반

solution = lambda left, right: sum(each if (temp := each ** 0.5) - int(temp) > 0 else - each for each in range(left, right + 1))

 

golang

import "math"

func solution(left int, right int) (sum int) {
	for i := left; i <= right; i++ {
		temp := math.Sqrt(float64(i))
		if temp-math.Trunc(temp) > 0 {
			sum += i
		} else {
			sum -= i
		}
	}
	return
}

Java

class Solution {
    public int solution(int left, int right) {
        int answer = 0;
        for (var i = left; i < right + 1; i++) {
            var count = 0;
            for (var j = 1; j < i + 1; j++) {
                if (i % j == 0) {
                    count++;
                }
            }
            if (count % 2 == 0) {
                answer += i;
            } else {
                answer -= i;
            }
        }
        return answer;
    }
}

class Solution {
    public int solution(int left, int right) {
        int answer = 0;
        for (var i = left; i < right + 1; i++) {
            var temp = Math.sqrt(i);
            answer += (temp - (int) temp != 0) ? i : -i;
        }
        return answer;
    }
}