arduino timer pseudocode

gistfile1.ino

float t_random[numLeds]; // random timer
float t_reset[numLeds]; // reset timer

if (millis() - t_random[i] > t_reset[i]) { // when you've surpassed a random time for an LED
     toggle_led[i]; // turn it on
     t_reset[i] = millis(); // make the reset time the current time
     t_random[i] = random(bottomRange, topRange); // create a new random timer value for that LED
}