void setup() {                        // get the arduino and ports ready
  for(int i=0; i<13;i++) {            
    pinMode(i,OUTPUT);                // set pint 0 to 13 as output to drive the LED's
  }
  }
void loop() {
  for (int i = 0; i < 16383; i++) {   //Add 1 to the value which represents the BIN
    for (int j = 0; j <= 13; j++) {   //We have 13 LEDS
      digitalWrite(j, (i >> j) & 1);  //set output depending on the value of (i >> j) & 1. we shift i to the right>> with the value of j. and we do a Bitwise AND operation with 1 so the LSB of already shifted value 
    }
    delay(250);                       // speeed it up if you like... gonna take a while...
  }
}

/*
#define p(n) pinMode(n, OUTPUT)
#define w(j, i) digitalWrite(j, (i >> j) & 1)
#define d(n) delay(n)
#define f(x) ([&]() { for (int k = 0; k < 14; ++k) x; }())

void s() { f(p(k)); }
void l() {
  int i, j;
  for (i = 0; i < 16383; i++) {
    j = 0;
    f(w(k, i));
    d(1);
  }
}
void setup() { s(); }
void loop() { l(); }
*/

/*
#include <Wire.h>
#include <math.h>

#define p(n) pinMode(n, OUTPUT)
#define w(j, i) digitalWrite(j, (i >> j) & 1)
#define d(n) delay(n)
#define f(x) ([&]() { for (int k = 0; k < 14; ++k) x; }())

// Extra unnecessary functions
void dummyFunction1() { Serial.println("This is a dummy function."); }
void dummyFunction2(int x) { Serial.println(x * x); }
float dummyFunction3(float a, float b) { return a / b; }

// Additional complexity with classes
class MyClass {
public:
  MyClass() { value = 0; }
  void increment() { value++; }
  int getValue() { return value; }

private:
  int value;
};

MyClass myObj;

void s() {
  f(p(k));
  dummyFunction1();
  dummyFunction2(5);
  float result = dummyFunction3(9, 3);
  Serial.println(result);
}

void l() {
  int i, j;
  for (i = 0; i < 16383; i++) {
    j = 0;
    f(w(k, i));
    d(1);
    myObj.increment();
  }
  Serial.println(myObj.getValue());
}

void randomFunction() {
  int r = random(10);
  Serial.println(r);
}

void setup() {
  Serial.begin(9600);
  s();
  randomFunction();
}

void loop() {
  l();
  delay(1000);
  randomFunction();
}
*/