Question

2648. Generate Fibonacci Sequence

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Description

Write a generator function that returns a generator object which yields the fibonacci sequence.

The fibonacci sequence is defined by the relation Xn = Xn-1 + Xn-2.

The first few numbers of the series are 0, 1, 1, 2, 3, 5, 8, 13.

 

Example 1:

Input: callCount = 5
Output: [0,1,1,2,3]
Explanation:
const gen = fibGenerator();
gen.next().value; // 0
gen.next().value; // 1
gen.next().value; // 1
gen.next().value; // 2
gen.next().value; // 3

Example 2:

Input: callCount = 0
Output: []
Explanation: gen.next() is never called so nothing is outputted

 

Constraints:

• 0 <= callCount <= 50

Solutions

Solution 1

function* fibGenerator(): Generator<number, any, number> {
  let a = 0;
  let b = 1;
  while (true) {
    yield a;
    [a, b] = [b, a + b];
  }
}

/**
 * const gen = fibGenerator();
 * gen.next().value; // 0
 * gen.next().value; // 1
 */