Question

2620. Counter

中文文档

Description

Given an integer n, return a counter function. This counter function initially returns n and then returns 1 more than the previous value every subsequent time it is called (n, n + 1, n + 2, etc).

 

Example 1:

Input: 
n = 10 
["call","call","call"]
Output: [10,11,12]
Explanation: 
counter() = 10 // The first time counter() is called, it returns n.
counter() = 11 // Returns 1 more than the previous time.
counter() = 12 // Returns 1 more than the previous time.

Example 2:

Input: 
n = -2
["call","call","call","call","call"]
Output: [-2,-1,0,1,2]
Explanation: counter() initially returns -2. Then increases after each sebsequent call.

 

Constraints:

• -1000 <= n <= 1000
• 0 <= calls.length <= 1000
• calls[i] === "call"

Solutions

Solution 1

function createCounter(n: number): () => number {
  let i = n;
  return function () {
    return i++;
  };
}

/**
 * const counter = createCounter(10)
 * counter() // 10
 * counter() // 11
 * counter() // 12
 */