Merge pull request #127 from sir-gon/feature/minimum-absolute-difference-in-an-array

[Hacker Rank]: Minimum Absolute Difference in an Array solved ✓

Author: sir-gon

src/hackerrank/implementation/minimumAbsoluteDifference.test.ts

@@ -0,0 +1,43 @@
+import logger from '../../logger';
+
+import { minimumAbsoluteDifference } from './minimumAbsoluteDifference';
+
+describe('Minimum Absolute Difference in an Array', () => {
+  it('Minimum Absolute Difference in an Array border case', () => {
+    expect.assertions(1);
+
+    expect(() => {
+      minimumAbsoluteDifference([]);
+    }).toThrow('Empty input');
+  });
+
+  it('Minimum Absolute Difference in an Array Test case 0', () => {
+    expect.assertions(1);
+
+    const input = [3, -7, 0];
+    const solutionFound = 3;
+
+    const calculated = minimumAbsoluteDifference(input);
+
+    logger.info(
+      `Minimum Absolute Difference in an Array Test case 0: ${calculated}`
+    );
+
+    expect(calculated).toStrictEqual(solutionFound);
+  });
+
+  it('Minimum Absolute Difference in an Array Test case 1', () => {
+    expect.assertions(1);
+
+    const input = [-59, -36, -13, 1, -53, -92, -2, -96, -54, 75];
+    const solutionFound = 1;
+
+    const calculated = minimumAbsoluteDifference(input);
+
+    logger.info(
+      `Minimum Absolute Difference in an Array Test case 1: ${calculated}`
+    );
+
+    expect(calculated).toStrictEqual(solutionFound);
+  });
+});

src/hackerrank/implementation/minimumAbsoluteDifference.ts

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+/**
+ * Minimum Absolute Difference in an Array
+ *
+ * https://www.hackerrank.com/challenges/minimum-absolute-difference-in-an-array
+ *
+ * The absolute difference is the positive difference between two values
+ * a and b, is written |a - b| or |b - a| and they are equal. If a = 3 and
+ * b = 2, |3 - 2| = |2 - 3| = 1. Given an array of integers, find the minimum
+ * absolute difference between any two elements in the array.
+ *
+ * # Example.
+ * arr = [-2, 2, 4]
+ *
+ * There are 3 pairs of numbers: [-2, 2], [-2, 4] and [2, 4]. The absolute
+ * differences for these pairs are |(-2)| - 2| = 4, |(-2) - 4| and |2 - 4| = 2.
+ * The minimum absolute difference is 2.
+ *
+ * # Function Description
+ *
+ * Complete the minimumAbsoluteDifference function in the editor below.
+ * It should return an integer that represents the minimum absolute difference
+ * between any pair of elements.
+ *
+ * minimumAbsoluteDifference has the following parameter(s):
+ *
+ * * int arr[n]: an array of integers
+ *
+ * # Returns
+ *
+ * * int: the minimum absolute difference found
+ * Input Format
+ *
+ * The first line contains a single integer n, the size of arr.
+ * The second line contains n space-separated integers, arr[i].
+ *
+ * # Constraints
+ * 2 <= n < 10<sup>5</sup>
+ * -10<sup>9</sup> <= arr[i] <= 10<sup>9</sup>
+ *
+ * Sample Input 0
+ * ```
+ * 3
+ * 3 -7 0
+ * ```
+ *
+ * # Sample Output 0
+ * ```
+ * 3
+ * ```
+ *
+ * # Explanation 0
+ *
+ * The first line of input is the number of array elements. The array,
+ * arr = [3, -7, 0] There are three pairs to test: (3, -7), (3, 0), and
+ * (-7, 0). The absolute differences are:
+ *
+ * |3 - -7| => 10
+ * |3 - 0| => 3
+ * |-7 0| => 7
+ *
+ * Remember that the order of values in the subtraction does not influence
+ * the result. The smallest of these absolute differences is 3.
+ *
+ * # Sample Input 1
+ * ```
+ * 10
+ * -59 -36 -13 1 -53 -92 -2 -96 -54 75
+ * ```
+ *
+ * # Sample Output 1
+ * ```
+ * 1
+ * ```
+ *
+ * # Explanation 1
+ *
+ * The smallest absolute difference is |-54 - -53| = 1.
+ *
+ * # Sample Input 2
+ * ```
+ * 5
+ * 1 -3 71 68 17
+ * ```
+ *
+ * # Sample Output 2
+ * ```
+ * 3
+ * ```
+ *
+ * # Explanation 2
+ *
+ * The minimum absolute difference is |71 - 68| = 3.
+ */
+
+import { logger as console } from '../../logger';
+
+export function minimumAbsoluteDifference(arr: number[]): number {
+  if (arr.length == 0) {
+    throw new Error('Empty input');
+  }
+
+  const sortedNums = arr.splice(0).sort();
+  console.log(`sortedNums: ${sortedNums}`);
+
+  let result: number = Math.abs(sortedNums[0] - sortedNums[1]);
+
+  for (let i = 0; i < sortedNums.length - 1; i++) {
+    const a = sortedNums[i];
+    const b = sortedNums[i + 1];
+
+    const diff = Math.abs(a - b);
+
+    console.debug(
+      `(i: ${i}, i+1: ${i + 1}) => |a - b| = |${a} - ${b}| = ${diff}`
+    );
+
+    result = Math.min(result, diff);
+  }
+
+  return result;
+}
+
+export default { minimumAbsoluteDifference };