int leds[3] = {11, 12, 13};
int buttons[3] = {2, 3, 4};

void setup() {

for (int i = 0; i < 3; i++) {
pinMode(leds[i], OUTPUT);
pinMode(buttons[i], INPUT_PULLUP);
}

}

void loop() {

for (int i = 0; i < 3; i++) {

if (digitalRead(buttons[i]) == LOW) {
digitalWrite(leds[i], HIGH);
}
else {
digitalWrite(leds[i], LOW);
}

}

}