feat(learn): add Implement Binary Search - Coding Interview Prep - Algorithms Challenges (#44386)

* basic challenge create, with two tests

* updated test

* minor update

* rewrote tests, making many out of one test func

* completed coding challenge and ran tests local

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search-method.md

Co-authored-by: Krzysztof G. <60067306+gikf@users.noreply.github.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search-method.md

Co-authored-by: Krzysztof G. <60067306+gikf@users.noreply.github.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search-method.md

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* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search-method.md

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* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search-method.md

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* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search-method.md

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* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search-method.md

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* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search-method.md

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* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search-method.md

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* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search-method.md

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* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

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* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Eric Cheng <ericcheng9316@gmail.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Eric Cheng <ericcheng9316@gmail.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Eric Cheng <ericcheng9316@gmail.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Eric Cheng <ericcheng9316@gmail.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Eric Cheng <ericcheng9316@gmail.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Eric Cheng <ericcheng9316@gmail.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

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* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Ilenia <nethleen@gmail.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Ilenia <nethleen@gmail.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Ilenia <nethleen@gmail.com>

* renamed doc, fixed typo, made testing consistent

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Krzysztof G. <60067306+gikf@users.noreply.github.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Krzysztof G. <60067306+gikf@users.noreply.github.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Krzysztof G. <60067306+gikf@users.noreply.github.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Krzysztof G. <60067306+gikf@users.noreply.github.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Krzysztof G. <60067306+gikf@users.noreply.github.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Krzysztof G. <60067306+gikf@users.noreply.github.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Krzysztof G. <60067306+gikf@users.noreply.github.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Krzysztof G. <60067306+gikf@users.noreply.github.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Krzysztof G. <60067306+gikf@users.noreply.github.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Krzysztof G. <60067306+gikf@users.noreply.github.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Krzysztof G. <60067306+gikf@users.noreply.github.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Krzysztof G. <60067306+gikf@users.noreply.github.com>

* Update curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

Co-authored-by: Ilenia <nethleen@gmail.com>

Co-authored-by: Krzysztof G. <60067306+gikf@users.noreply.github.com>
Co-authored-by: Eric Cheng <ericcheng9316@gmail.com>
Co-authored-by: Ilenia <nethleen@gmail.com>

curriculum/challenges/_meta/algorithms/meta.json

@@ -43,5 +43,9 @@
     [
       "587d825c367417b2b2512c8f",
       "Implement Merge Sort"
+    ],
+    [
+      "61abc7ebf3029b56226de5b6",
+      "Implement Binary Search"
     ]
   ]}

curriculum/challenges/english/10-coding-interview-prep/algorithms/implement-binary-search.md

@@ -0,0 +1,150 @@
+---
+id: 61abc7ebf3029b56226de5b6
+title: Implement Binary Search
+challengeType: 1
+forumTopicId: 487618
+dashedName: implement-binary-search
+---
+
+# --description--
+
+Binary search is an **O(log(n))** efficiency algorithm for searching a sorted array to find an element. It operates using the following steps:
+
+1. Find the middle `value` of a sorted array. If `value == target` return (found it!).
+1. If middle `value < target`, search right half of array in next compare.
+1. If middle `value > target`, search left half of array in next compare.
+
+As you can see, you are successively halving an array, which gives you the log(n) efficiency. For this challenge, we want you to show your work - how you got to the target value... the path you took!
+
+# --instructions--
+
+Write a function `binarySearch` that implements the binary search algorithm on an array, returning the path you took (each middle value comparison) to find the target in an array.
+
+The function takes a sorted array of integers and a target value as input. It returns an array containing (in-order) the middle value you found at each halving of the original array until you found the target value. The target value should be the last element of the returned array. If value not is found, return the string `Value Not Found`.
+
+For example, `binarySearch([1,2,3,4,5,6,7], 5)` would return `[4,6,5]`.
+
+For this challenge, when halving, you MUST use `Math.floor()` when doing division: `Math.floor(x/2)`. This will give a consistent, testable path.
+
+**Note:** The following array will be used in tests:
+
+```js
+const testArray = [
+  0, 1, 2, 3, 4, 5, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
+  23, 49, 70
+];
+```
+
+# --hints--
+
+`binarySearch` should be a function.
+
+```js
+assert(typeof binarySearch == 'function');
+```
+
+`binarySearch(testArray, 0)` should return `[13, 5, 2, 0]`.
+
+```js
+assert.deepEqual(binarySearch(_testArray, 0), [13, 5, 2, 0]);
+```
+
+`binarySearch(testArray, 1)` should return `[13, 5, 2, 0, 1]`.
+
+```js
+assert.deepEqual(binarySearch(_testArray, 1), [13, 5, 2, 0, 1]);
+```
+
+
+`binarySearch(testArray, 2)` should return `[13, 5, 2]`.
+
+```js
+assert.deepEqual(binarySearch(_testArray, 2), [13, 5, 2]);
+```
+
+`binarySearch(testArray, 6)` should return the string `Value Not Found`.
+
+```js
+assert.strictEqual(binarySearch(_testArray, 6), 'Value Not Found');
+```
+
+`binarySearch(testArray, 11)` should return `[13, 5, 10, 11]`.
+
+```js
+assert.deepEqual(binarySearch(_testArray, 11), [13, 5, 10, 11])
+```
+
+`binarySearch(testArray, 13)` should return `[13]`.
+
+```js
+assert.deepEqual(binarySearch(_testArray, 13), [13]);
+```
+
+
+# --seed--
+
+## --after-user-code--
+
+```js
+const _testArray = [
+  0, 1, 2, 3, 4, 5, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
+  23, 49, 70
+];
+```
+
+## --seed-contents--
+
+```js
+function binarySearch(searchList, value) {
+  let arrayPath = [];
+  return arrayPath;
+}
+```
+
+
+
+# --solutions--
+
+```js
+let binarySearch = (searchList, value) => {
+  let arrayPath = [];
+
+  // set initial L - M - R
+  let left = 0;
+  let right = searchList.length - 1;
+  let middle = Math.floor(right / 2);
+
+  // if first comparison finds value
+  if (searchList[middle] == value) {
+    arrayPath.push(searchList[middle]);
+    return arrayPath;
+  }
+
+  while (searchList[middle] !== value) {
+    // add to output array
+    arrayPath.push(searchList[middle]);
+
+    // not found
+    if (right < left) {
+      return 'Value Not Found';
+    }
+    // value is in left or right portion of array
+    // update L - M - R
+    if (searchList[middle] > value) {
+      right = middle - 1;
+      middle = left + Math.floor((right - left) / 2);
+    } else {
+      left = middle + 1;
+      middle = left + Math.floor((right - left) / 2);
+    }
+
+    // if found update output array and exit
+    if (searchList[middle] == value) {
+      arrayPath.push(searchList[middle]);
+
+      break;
+    }
+  }
+  return arrayPath;
+};
+```