Digital lock using arduino uno

HEY GUYS THIS IS THE CODE FOR DIGITAL LOCK USING ARDUINO UNO

PLEASE GO THROUGH IT

/*Circuit connections for LCD Interfacing:

 * LCD RS pin to digital pin 12

 * LCD Enable pin to digital pin 11

 * LCD D4 pin to digital pin 5

 * LCD D5 pin to digital pin 4

 * LCD D6 pin to digital pin 3

 * LCD D7 pin to digital pin 2

 * LCD R/W pin to ground

 * 10K resistor:

 * ends to +5V and ground

 * wiper to LCD VO pin (pin 3)

 *Circuit connections for Keypad Interfacing:

 */

#include <Keypad.h>

#include <LiquidCrystal.h>

LiquidCrystal lcd(12,11,5,4,3,2);

char* secretCode = "2218";//character pointer secretCode stores the starting address of the string "2218"

int p=0;

const byte rows = 4;//four rows

const byte cols = 3;//three columns

char keys[rows][cols] =

{

{'1','2','3'},

{'4','5','6'},

{'7','8','9'},

{'*','0','#'}

};

byte rowPins[rows] = {9,8,7,6};//connect to the row pinouts of the keypad

byte colPins[cols] = {12,11,10};//connect to the column pinouts of the keypad

Keypad nirma = Keypad(makeKeymap(keys), rowPins, colPins, rows, cols);

int redPin = 4;

int greenPin =2;

void setup()

{

  pinMode(redPin, OUTPUT);

  pinMode(greenPin, OUTPUT);

  lcd.begin(16,2);//set up the LCD's number of columns and rows

  lcd.print("Enter password ");

  //setLocked(true);

}

void loop()

{

  lcd.setCursor(0, 1);

  char input = nirma.getKey();//returns the key that is pressed

  for(int i=3;i>0;i--)//Loop controls no. of attempts(3)

  {

    for(int k=1;k<5;k++)//Loop controls no. of keypad presses(4)

    {

      if (input == '*' || input == '#')

      {

        p = 0;

        setLocked(true);

        lcd.println("Invalid numerals");//Red LED is on untill all 4 no.s have been pressed

      }

      else if(input == secretCode[p])

      {

        lcd.print("*");

        p++;

        if(p == 4)

        {

          setLocked(false);//Green LED glows when all 4 no.s have been entered

          lcd.println("Correct Password");

        }

      }

      else

      {

        lcd.print("*");

        p++;

        if(p == 4)

        {

          setLocked(true);

          lcd.println("I am locked.");

          lcd.println(i-1); lcd.print("trials left");

          if(i==1)

          {

            lcd.println("I am blocked.");

          }

        }

      }

    }

    delay(100);

  }

}

void setLocked(int locked)//user-defined function setlocked

{

  if(locked)

  {

    digitalWrite(redPin, HIGH);

    digitalWrite(greenPin, LOW);

  }

  else

  {

    digitalWrite(redPin, LOW);

    digitalWrite(greenPin, HIGH);

  }

}