ee1e8abd87
* feat(tools): add seed/solution restore script * chore(curriculum): remove empty sections' markers * chore(curriculum): add seed + solution to Chinese * chore: remove old formatter * fix: update getChallenges parse translated challenges separately, without reference to the source * chore(curriculum): add dashedName to English * chore(curriculum): add dashedName to Chinese * refactor: remove unused challenge property 'name' * fix: relax dashedName requirement * fix: stray tag Remove stray `pre` tag from challenge file. Signed-off-by: nhcarrigan <nhcarrigan@gmail.com> Co-authored-by: nhcarrigan <nhcarrigan@gmail.com>
118 lines
2.6 KiB
Markdown
118 lines
2.6 KiB
Markdown
---
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id: 5a23c84252665b21eecc7e7b
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title: Generator/Exponential
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challengeType: 5
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forumTopicId: 302275
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dashedName: generatorexponential
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---
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# --description--
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A generator is an executable entity (like a function or procedure) that contains code that yields a sequence of values, one at a time, so that each time you call the generator, the next value in the sequence is provided.
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Generators are often built on top of coroutines or objects so that the internal state of the object is handled "naturally".
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Generators are often used in situations where a sequence is potentially infinite, and where it is possible to construct the next value of the sequence with only minimal state.
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# --instructions--
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Write a function that uses generators to generate squares and cubes. Create a new generator that filters all cubes from the generator of squares.
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The function should return the \\( n^{th} \\) value of the filtered generator.
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For example for \\(n=7\\), the function should return 81 as the sequence would be 4, 9, 16, 25, 36, 49, 81. Here 64 is filtered out, as it is a cube.
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# --hints--
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`exponentialGenerator` should be a function.
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```js
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assert(typeof exponentialGenerator == 'function');
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```
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`exponentialGenerator()` should return a number.
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```js
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assert(typeof exponentialGenerator(10) == 'number');
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```
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`exponentialGenerator(10)` should return `144`.
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```js
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assert.equal(exponentialGenerator(10), 144);
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```
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`exponentialGenerator(12)` should return `196`.
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```js
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assert.equal(exponentialGenerator(12), 196);
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```
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`exponentialGenerator(14)` should return `256`.
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```js
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assert.equal(exponentialGenerator(14), 256);
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```
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`exponentialGenerator(20)` should return `484`.
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```js
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assert.equal(exponentialGenerator(20), 484);
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```
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`exponentialGenerator(25)` should return `784`.
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```js
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assert.equal(exponentialGenerator(25), 784);
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```
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# --seed--
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## --seed-contents--
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```js
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function exponentialGenerator(n) {
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}
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```
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# --solutions--
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```js
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function exponentialGenerator(n){
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function* PowersGenerator(m) {
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var n=0;
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while(1) {
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yield Math.pow(n, m);
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n += 1;
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}
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}
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function* FilteredGenerator(g, f){
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var value = g.next().value;
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var filter = f.next().value;
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while(1) {
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if( value < filter ) {
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yield value;
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value = g.next().value;
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} else if ( value > filter ) {
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filter = f.next().value;
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} else {
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value = g.next().value;
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filter = f.next().value;
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}
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}
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}
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var squares = PowersGenerator(2);
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var cubes = PowersGenerator(3);
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var filtered = FilteredGenerator(squares, cubes);
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var curr=0;
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for(var i=0;i<n;i++) curr=filtered.next();
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return curr.value;
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}
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```
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