2632. Curry

tags: leetcode 30 days js challenge Medium

2632. Curry

題目描述

Given a function fn, return a curried version of that function.

A curried function is a function that accepts fewer or an equal number of parameters as the original function and returns either another curried function or the same value the original function would have returned.

In practical terms, if you called the original function like sum(1,2,3), you would call the curried version like csum(1)(2)(3), csum(1)(2,3), csum(1,2)(3), or csum(1,2,3). All these methods of calling the curried function should return the same value as the original.

範例

Example 1:

Input: 
fn = function sum(a, b, c) { return a + b + c; }
inputs = [[1],[2],[3]]
Output: 6
Explanation:
The code being executed is:
const curriedSum = curry(fn);
curriedSum(1)(2)(3) === 6;
curriedSum(1)(2)(3) should return the same value as sum(1, 2, 3).

Example 2:

Input:
fn = function sum(a, b, c) { return a + b + c; }
inputs = [[1,2],[3]]
Output: 6
Explanation:
curriedSum(1, 2)(3) should return the same value as sum(1, 2, 3).

Example 3:

Input:
fn = function sum(a, b, c) { return a + b + c; }
inputs = [[],[],[1,2,3]]
Output: 6
Explanation:
You should be able to pass the parameters in any way, including all at once or none at all.
curriedSum()()(1, 2, 3) should return the same value as sum(1, 2, 3).

Example 4:

Input:
fn = function life() { return 42; }
inputs = [[]]
Output: 42
Explanation:
currying a function that accepts zero parameters should effectively do nothing.
curriedLife() === 42

Constraints:

• 1 <= inputs.length <= 1000
• 0 <= inputs[i][j] <= 10⁵
• 0 <= fn.length <= 1000
• inputs.flat().length == fn.length
• function parameters explicitly defined

解答

TypeScript

function curry(fn: Function): Function {
  const accumulator: unknown[] = [];

  return function curried(...args: unknown[]) {
    args.forEach((arg) => accumulator.push(arg));
    if (accumulator.length === fn.length) {
      return fn(...accumulator);
    }

    return (...nextArgs: unknown[]) => curried(...nextArgs);
  };
}

學這麼久今天才知道 function.length 是參數的數量ㄏㄏ
SheepSun, May 14, 2023

Reference

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