//Declare the necessary variables

int numStates=3;
int states[6];
int stateDelays[6];
int currentState;

bool A;//marks which set of lights are being cycled through currently
int MAX;//index for the 3rd light in the current set of lights
int MIN;//index for the 1st light in the current set of lights

void setup() {
    states[0] = 36;//red 1 + red 2
    states[1] = 34;//green 1 + red 2
    states[2] = 33;//amber 1 + red 2
    states[3] = 36;//red 2 + red 1
    states[4] = 20;//green 2 + red 1
    states[5] = 12;//amber 2 + red 1

    //setup the first set of lights (index 0 to 2 in the states array)
    A = true;
    MAX = 2;
    MIN = 0;

    stateDelays[0] = 2;//red and red combo
    stateDelays[1] = 10;//green and red combo
    stateDelays[2] = 2;//amber and red combo
    stateDelays[3] = 2;//red and red combo
    stateDelays[4] = 10;//red and green combo
    stateDelays[5] = 2;//red and amber combo

    DDRB = DDRB | B00111111; //set Arduino pins 8 to 13 as output
    int currentState = 0;//set the first state to 0
    PORTB = states[currentState];
}

void loop() {
    //assign the current state to port B
    PORTB = states[currentState];
    //wait in the current state for specified time
    delay(stateDelays[currentState]*1000);
    //call function to get the new state
    currentState = transition(currentState);
}

int transition(int currentState){
    //if the current state is the last index in the current set of lights
    if(currentState == MAX){
        if(A){
            //switch to the second set of lights
            MAX = 5;
            MIN = 3;
            A = false;
        }
        else{
            //switch to the first set of lights
            MAX = 2;
            MIN = 0;
            A = true;
        }
        //assign the current state to the first index in the next set of lights
        currentState=MIN;
    }else{
        currentState++;//otherwise transition normally
    }
    return currentState;
}