Merge pull request #7758 from ealvar3z/challenge-208_eax

add week 208 solutions in JS

3 files changed, 86 insertions, 0 deletions

diff --git a/challenge-208/ealvar3z/blog.txt b/challenge-208/ealvar3z/blog.txt
new file mode 100644
index 0000000000..436396a6f6
--- /dev/null
+++ b/challenge-208/ealvar3z/blog.txt
@@ -0,0 +1 @@
+https://eax.bearblog.dev/gang-of-misfits-and-their-arithmetic-progressions/
diff --git a/challenge-208/ealvar3z/js/ch-1.js b/challenge-208/ealvar3z/js/ch-1.js
new file mode 100644
index 0000000000..8caf69de9f
--- /dev/null
+++ b/challenge-208/ealvar3z/js/ch-1.js
@@ -0,0 +1,37 @@
+#!/usr/bin/env node
+
+const assert = require('assert');
+
+// Implementation
+function solve(a, b) {
+	const common = a.filter(e => b.includes(e));
+
+	const minimum_sum = common.reduce((acc, e) => {
+		const i = a.indexOf(e);
+		const j = b.indexOf(e);
+		const sum = i + j;
+
+		if (sum < acc.min_sum) {
+			return { elements: [e], min_sum: sum };
+		} else if (sum == acc.min_sum) {
+			return { elements: [...acc.elements, e], min_sum: sum };
+		} else {
+			return acc;
+		}
+	}, { elements: [], min_sum: Infinity });
+
+	return minimum_sum.elements;
+}
+
+// Tests
+const p = ["Perl", "Raku", "Love"];
+const q = ["Raku", "Perl", "Hate"];
+const r = solve(p, q);
+assert.deepStrictEqual(r.sort(), ["Perl", "Raku"]);
+
+const P = ["A", "B", "C"];
+const Q = ["D", "E", "F"];
+const R = solve(P, Q);
+assert.deepStrictEqual(R, []);
+
+console.log('All tests passed');
diff --git a/challenge-208/ealvar3z/js/ch-2.js b/challenge-208/ealvar3z/js/ch-2.js
new file mode 100644
index 0000000000..3b915a4157
--- /dev/null
+++ b/challenge-208/ealvar3z/js/ch-2.js
@@ -0,0 +1,48 @@
+#!/usr/bin/env node
+
+// Implementation
+function solve(misfits) {
+	const n = misfits.length;
+	
+	// elements
+	const elements = misfits.reduce((acc, val) => acc + val, 0);
+	const sum_of_elements = (n * (n + 1)) / 2;
+	const element_diff = sum_of_elements - elements;
+	
+	// squares
+	const squares = misfits.reduce((acc, val) => acc + val * val, 0);
+	const sum_of_squares = (n * (n + 1) * (2 * n + 1)) / 6;
+	const square_diff = sum_of_squares - squares;
+	
+
+	if (element_diff === 0 && square_diff === 0) {
+		return -1;
+	} else {
+		const missing = (element_diff * element_diff + square_diff) / (2 * element_diff);
+		const duplicate = missing - element_diff;
+		return { duplicate, missing };
+	}
+
+}
+
+// Tests
+const assert = require('assert');
+
+const a = [1, 2, 3, 4];
+const test_a = solve(a);
+assert.deepStrictEqual(test_a, -1);
+
+const b = [1, 2, 3, 3];
+const test_b = solve(b);
+assert.deepStrictEqual(test_b, { duplicate: 3, missing: 4 });
+
+const c = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+const test_c = solve(c);
+assert.deepStrictEqual(test_c, -1);
+
+const d = [1, 2, 2, 4];
+const test_d = solve(d);
+assert.deepStrictEqual(test_d, { duplicate: 2, missing: 3});
+
+
+console.log('All tests passed');