Fibonacci number

src/TechInterview/Fibonacci.java

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+package TechInterview;
+
+import java.util.function.LongSupplier;
+import java.util.stream.LongStream;
+
+/**
+ * Cracking the Code Interview
+ * My solutions of how to generate the nth Fibonacci number.
+ * Here are three different solutions to find this number
+ */
+
+public class Fibonacci {
+
+    public static void main(String[] args) {
+
+        System.out.println(fibStream(35));
+        System.out.println(fib(35));
+        System.out.println(iterFib(35));
+
+    }
+
+    // basic algorithm without cache
+
+    public static int fib(int n) {
+
+        if (n == 0) return 0;
+        if (n == 1) return 1;
+        return fib(n - 1) + fib(n - 2);
+
+    }
+
+    // iterative algorithm without cache
+
+    public static int iterFib(int n) {
+
+        return iter(1, 0, n);
+
+    }
+
+    private static int iter(int a, int b, int count) {
+
+        if (count == 0) return b;
+        return iter(a + b, a, count - 1);
+
+    }
+
+    //  solution with stream api
+
+    public static long fibStream(int n) {
+
+        return LongStream.generate(new FibonacciSupplier())
+                .skip(n - 1)
+                .findFirst().getAsLong();
+
+    }
+
+    private static class FibonacciSupplier implements LongSupplier {
+
+        private long prev = 0L;
+        private long next = 1L;
+
+        @Override
+        public long getAsLong() {
+            long current = next;
+            next = prev + current;
+            prev = current;
+            return current;
+        }
+
+    }
+}