40detectives

// I have some code that needs to use the following 
// construct repeatedly
for(i=0;i<classes.length;i++){
  var c = classes[i];
  for(j=0;j<centers.length;j++){
      var k = centers[k];

     // do something with [c,k], like,
     // demand[[c,k]] = expression;

40detectives

// This is an example of Reacts's useMemo hook, 
// useMemo only really does a "render memoization" for react internally, i.e.: skipping calculation in some renders.
// in this example I try to circumvent that and make useMemo to also cache previous calls in an object.

// ALSO: the ideal way of doing this for fibonacci would be doing the memoization in the fibonacci function itself, 
// that way you could remember all the n-1 fibonacci numbers after just one fibonacci(n) call.

import { useState, useMemo } from "react";

const fibonacci = (n) => {