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Fibonacci.java
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Fibonacci.java
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/*
* Title: Fibonacci
*
* Given an integer n, write a function to compute the nth Fibonacci number.
*
* Execution: javac Fibonacci.java && java Fibonacci
*
* For more details, check out http://www.byte-by-byte.com/fibonacci/
*/
public class Fibonacci {
public static long fibonacci(int x) {
if (x < 0) {
return -1;
}
if (x == 0) {
return 0;
}
long [] cache = new long[x + 1];
for (int i = 1; i < cache.length; i++) {
cache[i] = -1;
}
cache[1] = 1;
return fibonacci(x, cache);
}
public static long fibonacci(int x, long[] cache){
if (cache[x] > -1) {
return cache[x];
}
cache[x] = fibonacci(x-1, cache) + fibonacci(x-2, cache);
return cache[x];
}
// Sample test cases
public static void main(String[] args) {
assert fibonacci(1) == 1;
assert fibonacci(5) == 5;
assert fibonacci(10) == 55;
System.out.println("Passed all test cases");
}
}