TheAlgorithms · NitinRamnani · Oct 1, 2022
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+/**
+ * @function fibonacci
+ * @description Fibonacci is the sum of previous two fibonacci numbers.
+ * @param {Integer} N - The input integer
+ * @return {Integer} fibonacci of N.
+ * @see [Fibonacci_Numbers](https://en.wikipedia.org/wiki/Fibonacci_number)
+ */
+const fibonacci = (N) => {
+  if (!Number.isInteger(N)) {
+    throw new TypeError('Input should be integer')
+  }
+  const dp = new Map()
+  return fiboDP(N, dp)
+}
+
+const fiboDP = (N, dp) => {
+  if (N <= 1) return N
+
+  if (dp.has(N)) return dp.get(N)
+
+  const result = fiboDP(N - 1, dp) + fiboDP(N - 2, dp)
+  dp.set(N, result)
+  return result
+}
+
+export { fibonacci }
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+import { fibonacci } from '../FibonacciNumberRecursive'
+
+describe('Testing FibonacciNumberRecursive', () => {
+  it('fibonacci of 0', () => {
+    expect(fibonacci(0)).toBe(0)
+  })
+
+  it('fibonacci of 1', () => {
+    expect(fibonacci(1)).toBe(1)
+  })
+
+  it('fibonacci of 10', () => {
+    expect(fibonacci(10)).toBe(55)
+  })
+
+  it('fibonacci of 25', () => {
+    expect(fibonacci(25)).toBe(75025)
+  })
+
+  it('Testing for invalid type', () => {
+    expect(() => fibonacci('abc')).toThrowError()
+    expect(() => fibonacci()).toThrowError()
+  })
+})