add sol

leetcode/442.FindAllDuplicatesinanArray/FindAllDuplicatesinanArray.go

@@ -0,0 +1,28 @@
+// https://leetcode.com/problems/find-all-duplicates-in-an-array/description/
+
+package main
+
+import "fmt"
+
+func findDuplicates(nums []int) []int {
+	cnt := make(map[int]int)
+	res := []int{}
+
+	for _, num := range nums {
+		cnt[num]++
+		// fmt.Println(cnt)
+	}
+
+	for num, count := range cnt {
+		if count > 1 {
+			res = append(res, num)
+		}
+	}
+
+	return res
+}
+
+func main() {
+	nums := []int{4, 3, 2, 7, 8, 2, 3, 1}
+	fmt.Println(findDuplicates(nums))
+}