2019-11-05 02:09:40 -01:00
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---
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id: 5d792534f0eda837510e9192
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2020-08-25 02:19:45 -07:00
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title: Part 38
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2019-11-05 02:09:40 -01:00
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challengeType: 0
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---
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2020-11-27 19:02:05 +01:00
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# --description--
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2019-11-05 02:09:40 -01:00
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Now use the ternary operator in the last line to return `applyFunction(fn, args)` if the statement is true, and `match` otherwise.
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2020-11-27 19:02:05 +01:00
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# --hints--
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2019-11-05 02:09:40 -01:00
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2020-11-27 19:02:05 +01:00
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See description above for instructions.
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2019-11-05 02:09:40 -01:00
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2020-11-27 19:02:05 +01:00
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```js
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assert(applyFn('2+2*2') === '6' && applyFn('(2+2)*2') === '4*2');
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```
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2019-11-05 02:09:40 -01:00
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2020-11-27 19:02:05 +01:00
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# --seed--
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2019-11-05 02:09:40 -01:00
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2020-11-27 19:02:05 +01:00
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## --before-user-code--
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2019-11-05 02:09:40 -01:00
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2020-11-27 19:02:05 +01:00
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```html
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<!DOCTYPE html>
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<html lang="en">
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<head>
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<meta charset="UTF-8">
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<title>Spreadsheet</title>
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<style>
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#container {
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display: grid;
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grid-template-columns: 50px repeat(10, 200px);
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grid-template-rows: repeat(11, 30px);
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}
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.label {
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background-color: lightgray;
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text-align: center;
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vertical-align: middle;
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line-height: 30px;
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}
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</style>
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</head>
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<body>
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<div id="container">
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<div></div>
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</div>
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2019-11-05 02:09:40 -01:00
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```
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2020-11-27 19:02:05 +01:00
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## --after-user-code--
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2019-11-05 02:09:40 -01:00
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2020-11-27 19:02:05 +01:00
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```html
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</body>
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</html>
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```
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2019-11-05 02:09:40 -01:00
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2020-11-27 19:02:05 +01:00
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## --seed-contents--
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2019-11-05 02:09:40 -01:00
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```html
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<script>
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const infixToFunction = {
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"+": (x, y) => x + y,
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"-": (x, y) => x - y,
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"*": (x, y) => x * y,
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"/": (x, y) => x / y
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};
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const infixEval = (str, regex) =>
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str.replace(regex, (_, arg1, fn, arg2) =>
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infixToFunction[fn](parseFloat(arg1), parseFloat(arg2))
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);
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const highPrecedence = str => {
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const regex = /([0-9.]+)([*\/])([0-9.]+)/;
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const str2 = infixEval(str, regex);
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return str === str2 ? str : highPrecedence(str2);
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};
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const spreadsheetFunctions = {
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"": x => x
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};
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const applyFn = str => {
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const noHigh = highPrecedence(str);
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const infix = /([0-9.]+)([+-])([0-9.]+)/;
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const str2 = infixEval(noHigh, infix);
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const regex = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
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const toNumberList = args => args.split(",").map(parseFloat);
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const applyFunction = (fn, args) =>
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spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
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return str2.replace(
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regex,
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(match, fn, args) =>
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spreadsheetFunctions.hasOwnProperty(fn.toLowerCase())
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);
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}
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</script>
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```
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2020-11-27 19:02:05 +01:00
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# --solutions--
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2019-11-05 02:09:40 -01:00
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```html
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<script>
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const infixToFunction = {
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"+": (x, y) => x + y,
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"-": (x, y) => x - y,
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"*": (x, y) => x * y,
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"/": (x, y) => x / y
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};
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const infixEval = (str, regex) =>
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str.replace(regex, (_, arg1, fn, arg2) =>
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infixToFunction[fn](parseFloat(arg1), parseFloat(arg2))
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);
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const highPrecedence = str => {
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const regex = /([0-9.]+)([*\/])([0-9.]+)/;
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const str2 = infixEval(str, regex);
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return str === str2 ? str : highPrecedence(str2);
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};
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const spreadsheetFunctions = {
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"": x => x
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};
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const applyFn = str => {
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const noHigh = highPrecedence(str);
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const infix = /([0-9.]+)([+-])([0-9.]+)/;
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const str2 = infixEval(noHigh, infix);
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const regex = /([a-z]*)\(([0-9., ]*)\)(?!.*\()/i;
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const toNumberList = args => args.split(",").map(parseFloat);
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const applyFunction = (fn, args) =>
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spreadsheetFunctions[fn.toLowerCase()](toNumberList(args));
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return str2.replace(
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regex,
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(match, fn, args) =>
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spreadsheetFunctions.hasOwnProperty(fn.toLowerCase()) ? applyFunction(fn, args) : match
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);
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};
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</script>
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```
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