import java.util.HashMap;
public class CallsComparison {
private static HashMap<Long, Long> memory = new HashMap<Long, Long>();
private static HashMap<Long, Long> map = new HashMap<Long, Long>();
public static final long LOWER_BOUND = 200_000_000_000L;
public static final long NUMBER_OF_TRIES = 1_000L;
public static final long UPPER_BOUND = LOWER_BOUND + NUMBER_OF_TRIES;
private static long numCallsCoins = 0;
private static long numCallsChanger = 0;
public static void main(String[] args) {
memory.put(0L, 0L);
for (long i = LOWER_BOUND; i <= UPPER_BOUND; i++) {
changer(i);
}
memory = null;
for (long i = LOWER_BOUND; i <= UPPER_BOUND; i++) {
coins(i);
}
System.out.println("changer needed " + numCallsChanger
+ " function calls");
System.out.println("coins needed " + numCallsCoins + " function calls");
System.out.println("the call ratio changer/coins is: "
+ ((double) numCallsChanger / (double) numCallsCoins));
System.out.println("numCallsChanger - numCallsCoins = " + (numCallsChanger - numCallsCoins));
}
public static Long changer(long coin) {
numCallsChanger++;
if (!memory.containsKey(coin)) {
long tmp = changer(coin / 4L) + changer(coin / 3L)
+ changer(coin / 2L);
memory.put(coin, tmp > coin ? tmp : coin);
}
return memory.get(coin);
}
public static long coins(long n) {
numCallsCoins++;
if (!map.containsKey(n)) {
map.put(n, (n > (n / 2) + (n / 3) + (n / 4) ? n : coins(n / 2)
+ coins(n / 3) + coins(n / 4)));
}
return map.get(n);
}
}