2018-10-10 22:03:03 +00:00
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---
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id: 56533eb9ac21ba0edf2244c6
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2021-03-15 03:20:39 +00:00
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title: 排队
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2018-10-10 22:03:03 +00:00
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challengeType: 1
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2020-04-29 10:29:13 +00:00
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videoUrl: 'https://scrimba.com/c/ca8Q8tP'
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forumTopicId: 18307
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2021-01-13 02:31:00 +00:00
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dashedName: stand-in-line
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2018-10-10 22:03:03 +00:00
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---
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2020-12-16 07:37:30 +00:00
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# --description--
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2018-10-10 22:03:03 +00:00
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2021-03-15 03:20:39 +00:00
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在计算机科学中队列(<dfn>queue</dfn>)是一个抽象的数据结构(<dfn>Data Structure</dfn>),队列中的条目都是有秩序的。 新的条目会被加到队列的末尾,旧的条目会从队列的头部被移出。
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2018-10-10 22:03:03 +00:00
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2021-03-15 03:20:39 +00:00
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写一个函数 `nextInLine`,用一个数组(`arr`)和一个数字(`item`)作为参数。
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2018-10-10 22:03:03 +00:00
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2021-03-15 03:20:39 +00:00
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把数字添加到数组的结尾,然后移出数组的第一个元素。
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2018-10-10 22:03:03 +00:00
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2021-03-15 03:20:39 +00:00
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最后 `nextInLine` 函数应该返回被删除的元素。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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# --hints--
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2018-10-10 22:03:03 +00:00
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2021-03-15 03:20:39 +00:00
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`nextInLine([], 5)` 应该返回一个数字。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert.isNumber(nextInLine([], 5));
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2018-10-10 22:03:03 +00:00
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```
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2021-03-15 03:20:39 +00:00
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`nextInLine([], 1)` 应该返回 `1`
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2018-10-10 22:03:03 +00:00
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```js
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2020-12-16 07:37:30 +00:00
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assert(nextInLine([], 1) === 1);
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2018-10-10 22:03:03 +00:00
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```
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2021-03-15 03:20:39 +00:00
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`nextInLine([2], 1)` 应该返回 `2`
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2018-10-10 22:03:03 +00:00
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```js
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2020-12-16 07:37:30 +00:00
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assert(nextInLine([2], 1) === 2);
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2018-10-10 22:03:03 +00:00
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```
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2021-03-15 03:20:39 +00:00
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`nextInLine([5,6,7,8,9], 1)` 应该返回 `5`
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert(nextInLine([5, 6, 7, 8, 9], 1) === 5);
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```
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2018-10-10 22:03:03 +00:00
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2021-03-15 03:20:39 +00:00
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在 `nextInLine(testArr, 10)` 执行后 `testArr[4]` 应该是 `10`
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2020-04-29 10:29:13 +00:00
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2018-10-10 22:03:03 +00:00
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```js
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nextInLine(testArr, 10);
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assert(testArr[4] === 10);
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2018-10-10 22:03:03 +00:00
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```
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2020-04-29 10:29:13 +00:00
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2021-01-13 02:31:00 +00:00
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# --seed--
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## --before-user-code--
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```js
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var logOutput = [];
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var originalConsole = console
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function capture() {
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var nativeLog = console.log;
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console.log = function (message) {
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logOutput.push(message);
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if(nativeLog.apply) {
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nativeLog.apply(originalConsole, arguments);
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} else {
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var nativeMsg = Array.prototype.slice.apply(arguments).join(' ');
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nativeLog(nativeMsg);
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}
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};
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}
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function uncapture() {
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console.log = originalConsole.log;
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}
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capture();
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```
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## --after-user-code--
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```js
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uncapture();
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testArr = [1,2,3,4,5];
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(function() { return logOutput.join("\n");})();
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```
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## --seed-contents--
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```js
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function nextInLine(arr, item) {
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// Only change code below this line
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return item;
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// Only change code above this line
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}
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// Setup
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var testArr = [1,2,3,4,5];
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// Display code
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console.log("Before: " + JSON.stringify(testArr));
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console.log(nextInLine(testArr, 6));
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console.log("After: " + JSON.stringify(testArr));
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```
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2020-12-16 07:37:30 +00:00
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# --solutions--
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2021-01-13 02:31:00 +00:00
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```js
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var testArr = [ 1,2,3,4,5];
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function nextInLine(arr, item) {
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arr.push(item);
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return arr.shift();
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}
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```
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