int a = 13;     
int b = 12;      
int c = 11;    
int d = 10;    
int e = 9;     
int f = 8;    
int g = 7;

int swit1 = 2;
int swit2 = 3;
int swit3 = 4;
int swit4 = 5;
int led = 6;
void setup() {                

pinMode(a, OUTPUT);
pinMode(b, OUTPUT);   
pinMode(c, OUTPUT);
pinMode(d, OUTPUT);
pinMode(e, OUTPUT);
pinMode(f, OUTPUT);
pinMode(g, OUTPUT);
pinMode(swit1, INPUT);     
pinMode(swit2, INPUT);    
pinMode(swit3, INPUT);
pinMode(swit4, INPUT);

}


void loop() {

    if (digitalRead(swit1) ==LOW && digitalRead(swit2) ==LOW && digitalRead(swit3) ==LOW && digitalRead(swit4) ==LOW ){
         zero();
       }
    if (digitalRead(swit1) ==HIGH && digitalRead(swit2) ==LOW && digitalRead(swit3) ==LOW && digitalRead(swit4) ==LOW ){
        one();
       }
    if (digitalRead(swit1) ==LOW && digitalRead(swit2) ==HIGH && digitalRead(swit3) ==LOW && digitalRead(swit4) ==LOW ){
        tow();
       }
    if (digitalRead(swit1) ==HIGH && digitalRead(swit2) ==HIGH && digitalRead(swit3) ==LOW && digitalRead(swit4) ==LOW ){
        three();
       }
    if (digitalRead(swit1) ==LOW && digitalRead(swit2) ==LOW && digitalRead(swit3) ==HIGH && digitalRead(swit4) ==LOW ){
        four();
       }
    if (digitalRead(swit1) ==HIGH && digitalRead(swit2) ==LOW && digitalRead(swit3) ==HIGH && digitalRead(swit4) ==LOW ){
        five();
       }
    if (digitalRead(swit1) ==LOW && digitalRead(swit2) ==HIGH && digitalRead(swit3) ==HIGH && digitalRead(swit4) ==LOW ){
        six();
       }
    if (digitalRead(swit1) ==HIGH && digitalRead(swit2) ==HIGH && digitalRead(swit3) ==HIGH && digitalRead(swit4) ==LOW ){
        seven();
       }
    if (digitalRead(swit1) ==LOW && digitalRead(swit2) ==LOW && digitalRead(swit3) ==LOW && digitalRead(swit4) ==HIGH ){
        eghit();
       }
    if (digitalRead(swit1) ==HIGH && digitalRead(swit2) ==LOW && digitalRead(swit3) ==LOW && digitalRead(swit4) ==HIGH ){
        nine();
       }
    if (digitalRead(swit1) && digitalRead(swit2) && digitalRead(swit3) && digitalRead(swit4)){
        digitalWrite(led,HIGH);
        off();
       }
       else{
         off();
         digitalWrite(led, LOW);
       }
  }  

  
   
  
    

void off()
{  digitalWrite(a, HIGH);
   digitalWrite(b, HIGH);
   digitalWrite(c, HIGH);
   digitalWrite(d, HIGH);       //off
   digitalWrite(e, HIGH);
   digitalWrite(f, HIGH);
   digitalWrite(g, HIGH);
  }
void zero()
{ digitalWrite(a, LOW);
  digitalWrite(b, LOW);
  digitalWrite(c, LOW);
  digitalWrite(d, LOW);       //0
  digitalWrite(e, LOW);
  digitalWrite(f, LOW);
  digitalWrite(g, HIGH);
  }
void one()
{
  digitalWrite(a, HIGH);
  digitalWrite(b, LOW);
  digitalWrite(c, LOW);
  digitalWrite(d, HIGH);       // 1
  digitalWrite(e, HIGH);
  digitalWrite(f, HIGH);
  digitalWrite(g, HIGH);}
void tow()
{
  digitalWrite(a, LOW);
  digitalWrite(b, LOW);
  digitalWrite(c, HIGH);      // 2
  digitalWrite(d, LOW);
  digitalWrite(e, LOW);
  digitalWrite(f, HIGH);
  digitalWrite(g, LOW);}
void three()
{
  digitalWrite(a, LOW);
  digitalWrite(b, LOW);
  digitalWrite(c, LOW);
  digitalWrite(d, LOW);      // 3
  digitalWrite(e, HIGH);
  digitalWrite(f, HIGH);
  digitalWrite(g, LOW);}
void four()
{
  digitalWrite(a, HIGH);
  digitalWrite(b, LOW);
  digitalWrite(c, LOW);
  digitalWrite(d, HIGH);
  digitalWrite(e, HIGH);     // 4
  digitalWrite(f, LOW);
  digitalWrite(g, LOW);}
void five()
{
  digitalWrite(a, LOW);
  digitalWrite(b, HIGH);
  digitalWrite(c, LOW);
  digitalWrite(d, LOW);
  digitalWrite(e, HIGH);     // 5
  digitalWrite(f, LOW);
  digitalWrite(g, LOW);}
void six()
{
  digitalWrite(a, LOW);
  digitalWrite(b, HIGH);
  digitalWrite(c, LOW);
  digitalWrite(d, LOW);    // 6
  digitalWrite(e, LOW);
  digitalWrite(f, LOW);
  digitalWrite(g, LOW);}
void seven()
{
  digitalWrite(a, LOW);
  digitalWrite(b, LOW);
  digitalWrite(c, LOW);
  digitalWrite(d, HIGH);
  digitalWrite(e, HIGH);   // 7
  digitalWrite(f, HIGH);
  digitalWrite(g, HIGH);}
void eghit()
{
  digitalWrite(a, LOW );
  digitalWrite(b, LOW);
  digitalWrite(c, LOW);
  digitalWrite(d, LOW);
  digitalWrite(e, LOW);     // 8
  digitalWrite(f, LOW);
  digitalWrite(g, LOW);}
void nine()
{
  digitalWrite(a, LOW);
  digitalWrite(b, LOW);
  digitalWrite(c, LOW);
  digitalWrite(d, HIGH);
  digitalWrite(e, HIGH);    // 9
  digitalWrite(f, LOW);
  digitalWrite(g, LOW);
  
}