go: add «350. Intersection of Two Arrays II»

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

go/intersection-of-two-arrays-ii.go

@@ -0,0 +1,31 @@
+package main
+
+func intersect(nums1, nums2 []int) []int {
+	count := func(nums []int) map[int]int {
+		freqs := make(map[int]int)
+		for _, x := range nums {
+			freqs[x]++
+		}
+		return freqs
+	}
+
+	freqs1 := count(nums1)
+	freqs2 := count(nums2)
+	if len(freqs1) > len(freqs2) {
+		freqs1, freqs2 = freqs2, freqs1
+	}
+
+	intersected := []int{}
+	for x, count1 := range freqs1 {
+		count2, found := freqs2[x]
+		if !found {
+			continue
+		}
+
+		for range min(count1, count2) {
+			intersected = append(intersected, x)
+		}
+	}
+
+	return intersected
+}