// 319. Bulb Switcher #include #include /* * there are 'n' light bulbs that are initially off. you first turn on all the * bulbs, then you turn off every second bulb. on the third round, you toggle * every third bulb (turning on if it is off or vice-versa). for the i'th round, * you toggle every 'i' bulb for the n'th round, you only toggle the last bulb. * return the number that on after 'n' */ int bulbSwitch(int n) { return sqrt(n); } int main() { printf("%d\n", bulbSwitch(3)); // expect: 1 printf("%d\n", bulbSwitch(0)); // expect: 0 printf("%d\n", bulbSwitch(1)); // expect: 1 }