Question

Anyone good at coding in C. i am lost, i need to create a code for a digital lock. the code must allow ten correct 4 digit pins to be entered, but that is the max. the idea is only 10 people can enter a secure room and once 10 are in no one else can get in untill someone leaves.

Answer 1

Hi,

The problem has been resolved. The digital lock has been created successfully. This lock will ask you to input 4 digit pin. Once you input the correct pin this will get you enter. I have set a hard coded pin that is '1234'.Now who will put the pin 1234 will enter the room. this will allow only 10 people to enter. After 10 it will show you that the room is full.

Please find the below screenshot of running code:

Screenshot:

Code:

----------------

#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <ctype.h>
#define MAX_LIMIT 20

bool verifyInput(char str[]){

   for (int i=0; i<4; i++)
{

if (isdigit(str[i]) == 0)
return false;
}

return true;
}

bool verifyPin(char str[]){
   char pin[]="1234";

   str[strlen(str)-1] = '\0';

   if (strcmp(str,pin) == 0)
       return true;
   else
       return false;
}

int main () {

char str[MAX_LIMIT];
  
int maxTry=10;

do {
        printf("For login, Please enter 4 digit pin:\n");
   fgets(str, MAX_LIMIT, stdin);
   printf("The Input pin is: %s\n", str);
   int len = strlen(str);
   len--;
   printf("Len : %d\n", len);
   if(len!=4){
      printf("Wrong pin!! You have to enter 4 digit pin\n\n");
   }
   else{
         
       bool isValid= verifyInput(str);
       printf("isValid: %d\n", isValid);
       if(isValid==1){
           bool isVerified = verifyPin(str);

           if(isVerified==1){
               printf("Verification Done!! You are in...\n\n");
               maxTry--;
           }
           else{
               printf("Wrong pin!! Try again...\n");
           }

       }
      
   }   
}while( maxTry>0 );

if(maxTry==0){
    printf("Room is full\n");
}

return 0;
}

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The problem has been resolved, I hope you will like the solution. If you have any question or query regarding this problem or other, please comment below and give the positive rating.

Thank You!! Happy Learning!! Keep Chegging!!