------ 17
function triangleOfDolar(number) {
    let printDolar = '';

    for (let i = 0; i < number; i++) {
        printDolar += '$';
        console.log(printDolar);
    }
}
------ 18

function checkMovie(arr) {
    let dayInWeek = 0;
    let incomingDay = arr[1].toLowerCase();
    let incomingMovie = arr[0].toLowerCase();

    switch (incomingDay) {
        case 'monday':
            dayInWeek = 1;
            break;
        case 'tuesday':
            dayInWeek = 2;
            break;
        case 'wednesday':
            dayInWeek = 3;
            break;
        case 'thursday':
            dayInWeek = 4;
            break;
        case 'friday':
            dayInWeek = 5;
            break;
        case 'saturday':
            dayInWeek = 6;
            break;
        case 'sunday':
            dayInWeek = 7;
            break;
        default:
            console.log('error');
            break;
    }

    let cinemaInfo = {};
    cinemaInfo['the godfather'] = [12, 10, 15, 12.50,   15, 25, 30];
    cinemaInfo["schindler's list"] = [8.50, 8.50, 8.50, 8.50, 8.50, 15, 15];
    cinemaInfo['casablanca'] = [8, 8, 8, 8, 8, 10, 10];
    cinemaInfo['the wizard of oz'] = [10, 10, 10, 10, 10, 15, 15];

    for(key in cinemaInfo){
        let value = cinemaInfo[key];
        if (key == incomingMovie) {
            console.log(value[dayInWeek -1]);
        } else{
          console.log('error')
        }
    }
}

------ 19
function quadraticEquation(a, b ,c) {


    let d = Math.pow(b,2) - (4 * a * c);

    if (d < 0) {
        console.log('No');
    } else if (d === 0) {
        let x = b * -1 / (2 * a);
        console.log(x);
    } else{
        let x1 = (((b * -1) + (Math.sqrt(d))) / (2 * a));
        let x2 = (((b * -1) - (Math.sqrt(d))) / (2 * a));

        console.log(Math.min(x1,x2));
        console.log(Math.max(x1,x2));
    }
}

------ 20

function multiplicationTable(tableSize) {
    let openTag = '<tr><th>';
    let middleTag = '</th><th>';
    let closeTag = '</th></tr>';
    let openTableTag = '<table border="1">';
    let closeTableTag = '</table>';

    console.log(openTableTag);
    let result = '  ';
    for (let i = 0; i <= tableSize; i++) {
        if (i == 0) {
            result += openTag + 'x';
        }
        else if (i == tableSize) {
            result += middleTag + i + closeTag;
        } else {
            result += middleTag + i;
        }
    }

    console.log(result);
    result = '  ';

    for (let i = 1; i <= tableSize; i++) {
        result += openTag + i + '</th>';
        for (let j = 1; j <= tableSize; j++) {
            result += '<td>' + `${j * i}` + '</td>';
        }
        result += '</tr>';

        console.log(result);
        result = '  ';

    }

    console.log(closeTableTag);
}

------- 21

function printSquare(squareSize) {
    const wall = '-';
    const corner = '+';
    const upperWall = '|';
    const emptySpace = ' ';
    let middleLine = Math.ceil(squareSize / 2);

    for (let i = 0; i < (middleLine * 2) - 1 ; i++) {
        if (i === 0 || i === (middleLine * 2) - 2 || i === middleLine - 1) {
            console.log('+' + Array(squareSize - 1).join("-") + '+' + Array(squareSize - 1).join("-") + '+');
        } else {
            console.log('|' + Array(squareSize - 1).join(" ") + '|' + Array(squareSize - 1).join(" ") + '|');
        }
    }
}

-------- 22

function calendar([day, month, year])
{
    // TODO: return the HTML text holding the calendar table

    month--; // months in Date() are [0...11], not [1...12]
    let daysInMonth = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
    if (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0))
        daysInMonth[1] = 29; // leap year

    // Print the calendar table header
    let html = '<table>\n';
    html += '  <tr><th>Sun</th><th>Mon</th><th>Tue</th><th>Wed</th><th>Thu</th><th>Fri</th><th>Sat</th></tr>\n';

    // Print the days of the previous month
    let week = 0;
    let date = new Date(year, month, 1);
    let dayOfWeek = date.getDay();
    let firstDayPrevMonth = daysInMonth[(month-1 + 12) % 12]-dayOfWeek;
    if (dayOfWeek > 0)
        html += '  <tr>';
    for (let i=1; i<=dayOfWeek; i++) {
        html += '<td class="prev-month">' + (firstDayPrevMonth + i) + '</td>';
        week++;
    }

    // Print the days of the current month
    let monthDaysCount = daysInMonth[month];
    for (let i=1; i<=monthDaysCount; i++) {
        if (week == 0)
            html += '  <tr>';
        if (day == i)
            html += '<td class="today">' + i + '</td>';
        else
            html += '<td>' + i + '</td>';
        week++;
        if (week == 7) {
            html += '</tr>\n';
            week=0;
        }
    }

    // Print the days of the next month
    for (let i=1; week!=0; i++) {
        html += '<td class="next-month">' + i + '</td>';
        week++;
        if (week == 7) {
            html += '</tr>\n';
            week = 0;
        }
    }

    html += '</table>';
    return html;
}