A refactored solution for Arduino test

Arduino Timer Test.c

#include <LiquidCrystal.h>

int buttonPin = 7;
int ledPin =  13;
int buttonState = 0;
boolean on = false;
int flag = 0;
int S = 05; // count seconds
int M = 00; // count minutes
int H = 00; // count hours
//initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2); // pins connected to LCD

void setup()
{
    pinMode(ledPin, OUTPUT);
    pinMode(buttonPin, INPUT);
    lcd.begin(16, 2);
    lcd.clear();
}

void loop() {
    buttonState = digitalRead(buttonPin);
    timeOut = (H == 0 && M == 0 && S == 0)
    on = (buttonState == HIGH) ? true : false;
    currentState = (on == true && timeOut) ? LOW : HIGH

    digitalWrite(ledPin, currentState);

    while (currentState == HIGH) {
        S = S - 1
        lcd.setCursor(1,0);
        lcd.print("Remaining");
        lcd.setCursor(6,1);
        lcd.print(":");
        lcd.setCursor(9,1);
        lcd.print(":");
        delay(1000);

        if (S == 0) {
            M--;
            S = 05;
        }

        if (M == 0) {
            H--;
            M = 00;
        }

        if (H == 0) {
            H = 00;
            M = 00;
            S = 05;
        }
    }

    lcd.clear();
    lcd.display();
    lcd.setCursor(0,0);
    lcd.print("Your laundry is ");
    lcd.setCursor(4,1);
    lcd.print("DONE!");
    delay(300);

    return 0;
}