go: add «624. Maximum Distance in Arrays»

Signed-off-by: Matej Focko <me@mfocko.xyz>

go/maximum-distance-in-arrays.go

@@ -0,0 +1,40 @@
+package main
+
+type Range struct {
+	min, max int
+}
+
+func RangeFromArray(array []int) Range {
+	return Range{
+		min: array[0],
+		max: array[len(array)-1],
+	}
+}
+
+func (r *Range) Update(subarray []int) {
+	r.min = min(r.min, subarray[0])
+	r.max = max(r.max, subarray[len(subarray)-1])
+}
+
+func abs(x int) int {
+	return max(-x, x)
+}
+
+func RangeMaxDistance(x, y Range) int {
+	return max(
+		abs(x.min-y.max),
+		abs(y.min-x.max),
+	)
+}
+
+func maxDistance(arrays [][]int) int {
+	foundDistance := 0
+
+	extremes := RangeFromArray(arrays[0])
+	for i := 1; i < len(arrays); i++ {
+		foundDistance = max(foundDistance, RangeMaxDistance(extremes, RangeFromArray(arrays[i])))
+		extremes.Update(arrays[i])
+	}
+
+	return foundDistance
+}