Given a function fn, return a memoized version of that function.
A memoized function is a function that will never be called twice with the same inputs. Instead it will return a cached value.
+ +You can assume there are 3 possible input functions: sum, fib, and factorial.
sum accepts two integers a and b and returns a + b. Assume that if a value has already been cached for the arguments (b, a) where a != b, it cannot be used for the arguments (a, b). For example, if the arguments are (3, 2) and (2, 3), two separate calls should be made.fib accepts a single integer n and returns 1 if n <= 1 or fib(n - 1) + fib(n - 2) otherwise.factorial accepts a single integer n and returns 1 if n <= 1 or factorial(n - 1) * n otherwise.+
Example 1:
+ ++Input: +fnName = "sum" +actions = ["call","call","getCallCount","call","getCallCount"] +values = [[2,2],[2,2],[],[1,2],[]] +Output: [4,4,1,3,2] +Explanation: +const sum = (a, b) => a + b; +const memoizedSum = memoize(sum); +memoizedSum(2, 2); // "call" - returns 4. sum() was called as (2, 2) was not seen before. +memoizedSum(2, 2); // "call" - returns 4. However sum() was not called because the same inputs were seen before. +// "getCallCount" - total call count: 1 +memoizedSum(1, 2); // "call" - returns 3. sum() was called as (1, 2) was not seen before. +// "getCallCount" - total call count: 2 ++ +
Example 2:
+ ++Input: +fnName = "factorial" +actions = ["call","call","call","getCallCount","call","getCallCount"] +values = [[2],[3],[2],[],[3],[]] +Output: [2,6,2,2,6,2] +Explanation: +const factorial = (n) => (n <= 1) ? 1 : (n * factorial(n - 1)); +const memoFactorial = memoize(factorial); +memoFactorial(2); // "call" - returns 2. +memoFactorial(3); // "call" - returns 6. +memoFactorial(2); // "call" - returns 2. However factorial was not called because 2 was seen before. +// "getCallCount" - total call count: 2 +memoFactorial(3); // "call" - returns 6. However factorial was not called because 3 was seen before. +// "getCallCount" - total call count: 2 ++ +
Example 3:
+ ++Input: +fnName = "fib" +actions = ["call","getCallCount"] +values = [[5],[]] +Output: [8,1] +Explanation: +fib(5) = 8 // "call" +// "getCallCount" - total call count: 1 ++ +
+
Constraints:
+ +0 <= a, b <= 1051 <= n <= 101 <= actions.length <= 105actions.length === values.lengthactions[i] is one of "call" and "getCallCount"fnName is one of "sum", "factorial" and "fib"