pic 4*4 keyboard scanning program

#include

             
 __CONFIG(0x1832);    
const char TABLE[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0X82,0XF8,0X80,0X90}; //Define the data table of constants 0-9   

 volatile unsigned char result=0,temp=0,f=0;  
 volatile unsigned int total=0,ge=0,shi=0,bai=0,qian=0,c=1; 
 void delay(); //delay function declaration 
 void init(); //I/O port initialization function declaration 
 void s CAN (); //Key scanning program declaration 
 void display(unsigned int x); //Display function declaration 
//--------------------------------------------------- 
                             //Main program   
void main() 
{ 
   init(); //Call initialization subroutine 
  while(1) //Loop work 
    { 
          
       scan();                 
       display(result);  
    } 
 } 
  
//--------------------------------------------------- 
//Initialization function 
void init()  
 { 
   
  ADCON1=0X07; //Set port A as a normal I/O port 
  TR ISA =0B00000000; //Set the high 2 bits of port A to output and the low 4 bits to input 
  TRISC=0B11110000; //Set the high 4 bits of port C as input and the low 4 bits as output 
  TRISD=0X00; //Set port D as output 
  PORTA=0XFF;               
  PORTD=0XFF; //Clear all displays first 
 } 

//-----------------------------------------------3--- 
//Key scanning program 
void scan(){  
               PORTC=0xff; 
               RC3=0; { if(RC4==0) result=1; if(RC5==0) result=2; if(RC6==0) result=3; if(RC7==0) result=4;} 
                
               
               PORTC=0xff; 
               RC2=0; { if(RC4==0) result=5; if(RC5==0) result=6; if(RC6==0) result=7; if(RC7==0) result=8;} 

               
               PORTC=0xff; 
               RC1=0; { if(RC4==0) result=9; if(RC5==0) result=10; if(RC6==0) result=11; if(RC7==0) result=12;} 
               
              
               PORTC=0xff; 
               RC0=0; { if(RC4==0) result=13; if(RC5==0) result=14; if(RC6==0) result=15; if(RC7==0) result=16;} 
            // if(temp!=result) {f++; if(f==1) qian=1000*result ; if(f==2) bai=100*result; if(f==3) shi=10*result; if(f==4) ge=result; } if(f==4) while(1){total=ge+shi+bai+qian; display(total); }  
  
 } 

//---------------------------------------------------------------- 
//Display program 
 void display(unsigned int x) // Voltage display function   
   { 
    
     unsigned int g,s,b,q; //define 6 temporary variables 
    // temp=result; c=1; 
     q=x/1000; 
     b=x%1000/100; //find the thousands displayed         
     s=x%100/10; //find the hundreds displayed 
     g=x%10; //find the tens displayed 
   
     PORTD=TABLE[q]; //display a decimal point 
     PORTA=0B111111110; //RA0 output lowlevel , light up the thousands display      
     delay(1);  

     PORTD=TABLE[b]; //Look up the table to get the code for the hundreds display 
     PORTA=0B11111101; //RA1 outputs low level, light up the hundreds display 
     delay(1); //Delay for a certain time to ensure the display brightness 

     PORTD=TABLE[s]; //Look up the table to get the code for the tens display 
     PORTA=0B11111011; //RA2 outputs low level, light up the tens display 
     delay(1); //Delay for a certain time to ensure the brightness 

     PORTD=TABLE[g]; //Look up the table to get the code for the tens display 
     PORTA=0B11110111; //RA3 outputs low level, light up the tens display 
     delay(1); //Delay for a certain time to ensure the brightness 

     PORTD=0xff; 

   }  
//------------------------------------------------------------------ 
//Delay program 
void delay() //Delay program 
    { 
     int i; //Define integer variables 
     for(i=0x100;i--;); //Delay 
    }