[Lv2] 멀쩡한 사각형

https://programmers.co.kr/learn/courses/30/lessons/62048

코딩테스트 연습 - 멀쩡한 사각형

 

좌표 평면 접근

 

let getGCD = (a, b) => (b > 0 ? getGCD(b, a % b) : a);
let getYVal = (val) => -(y / x) * val + y;
 
let x;
let y;
 
function solution(w, h) {
    var answer = 0;
    let GCD = getGCD(w, h);
    let num = 1;
    x = w / GCD;
    y = h / GCD;
 
    if(x === y) return w * h - h;
    
    count = 0;
    let pre = y;
    let xVal = 1;
 
    while(xVal <= x) {
        count += pre - Math.floor(getYVal(xVal));
        pre = Math.ceil(getYVal(xVal));
        xVal++;
    }
 
    while(1) {
        if(x * num === w) break;
        num++;
    }
 
    let total = num * count;
 
    answer = w * h - total;
 
    return answer;
}   
 
console.log(solution(3,3));