[프로그래머스]부족한 금액 계산하기

function solution(price, money, count) {
    var answer = -1;
    let sumPrice = 0;
    
    for (let i = 0; i <= count; i++) {
        sumPrice += price * i;
    }
    
    answer = sumPrice - money;
    return answer <= 0 ? 0 : answer;
}