add kata

5kyu/closest-and-smallest/solution.ts

@@ -0,0 +1,60 @@
+const weight = (s: string): number => s.split('').reduce((acc, cur) => acc + parseInt(cur), 0);
+
+const sortWeightInfo = <T extends WeightInfo | DiffInfo>(a: T, b: T): number => {
+  if (a[0] !== b[0]) {
+    return a[0] - b[0];
+  } else if (a[1] !== b[1]) {
+    return a[1] - b[1];
+  } else {
+    return a[2] - b[2];
+  }
+}
+
+type WeightInfo = [
+  number, // weight
+  number, // index
+  number  // number
+];
+type DiffInfo = [
+  number, // weight difference
+  number, // weight sum
+  number, // index sum
+  number, // index of first number
+  number  // index of second number
+];
+
+export function closest(strng: string): number[][] {
+  if (strng === '') return [];
+
+  const weights: WeightInfo[] = strng
+    .split(' ')
+    .map((s, i) => [weight(s), i, parseInt(s)]);
+
+  // calculate all weight differences, weight sum, and index sum
+  const diffs: DiffInfo[] = [];
+  for (const [weight, index, num] of weights) {
+    for (let i = index + 1; i < weights.length; i++) {
+      if(i >= weights.length) break;
+
+      const [weight2, index2, num2] = weights[i];
+      const weightDiff = Math.abs(weight - weight2);
+      const weightSum = weight + weight2;
+      const indexSum = index + index2;
+      diffs.push([weightDiff, weightSum, indexSum, index, index2]);
+    }
+  }
+
+  // sort by weight difference, weight sum, and index sum
+  diffs.sort(sortWeightInfo);
+
+  const minimumDiff = diffs[0]
+  const firstNumIndex = minimumDiff[3];
+  const secondNumIndex = minimumDiff[4];
+
+  const result = [
+    weights[firstNumIndex],
+    weights[secondNumIndex]
+  ].sort(sortWeightInfo)
+
+  return result;
+}