const byte PinLedRed [] = { 10,  3, 12,  5 };
const byte PinLedGrn [] = { 11,  4, 13,  6 };

const byte PinSw     [] = { A0, A3, A1, A2 };
const int  Nsw          = sizeof(PinSw);

enum { Off = LOW, On = HIGH };

// -----------------------------------------------------------------------------
void loop ()
{
    for (int n = 0; n < Nsw; n++) {
        byte val = digitalRead (PinSw [n]);
        digitalWrite (PinLedRed [n],   val);
        digitalWrite (PinLedGrn [n], ! val);
    }
}

void setup ()
{
    Serial.begin (9600);

    for (int n = 0; n < Nsw; n++) {
        pinMode (PinLedRed [n], OUTPUT);
        pinMode (PinLedGrn [n], OUTPUT);
        pinMode (PinSw     [n], INPUT_PULLUP);

        digitalWrite (PinLedRed [n], On);
        digitalWrite (PinLedGrn [n], On);

        delay (500);
        digitalWrite (PinLedRed [n], Off);
        digitalWrite (PinLedGrn [n], Off);
    }
}