From 5f7b8443ef45febfc2690f9a0a5cbfe3f4ca5040 Mon Sep 17 00:00:00 2001
From: ashing <axingfly@gmail.com>
Date: Wed, 31 Jan 2024 12:26:21 +0800
Subject: [PATCH] feat: 2670. Find the Distinct Difference Array

Signed-off-by: ashing <axingfly@gmail.com>
---
 ...670. Find the Distinct Difference Array.go | 24 ++++++++++++++
 ...Find the Distinct Difference Array_test.go | 32 +++++++++++++++++++
 2 files changed, 56 insertions(+)
 create mode 100644 leetcode/2670/2670. Find the Distinct Difference Array.go
 create mode 100644 leetcode/2670/2670. Find the Distinct Difference Array_test.go

diff --git a/leetcode/2670/2670. Find the Distinct Difference Array.go b/leetcode/2670/2670. Find the Distinct Difference Array.go
new file mode 100644
index 0000000..f36c8bc
--- /dev/null
+++ b/leetcode/2670/2670. Find the Distinct Difference Array.go	
@@ -0,0 +1,24 @@
+package _670
+
+func distinctDifferenceArray(nums []int) []int {
+	n := len(nums)
+	diff := make([]int, n)
+	prefixSet := make(map[int]bool)
+	suffixSet := make(map[int]int)
+
+	// Initialize suffix set with counts
+	for _, num := range nums {
+		suffixSet[num]++
+	}
+
+	for i, num := range nums {
+		prefixSet[num] = true
+		suffixSet[num]--
+		if suffixSet[num] == 0 {
+			delete(suffixSet, num)
+		}
+
+		diff[i] = len(prefixSet) - len(suffixSet)
+	}
+	return diff
+}
diff --git a/leetcode/2670/2670. Find the Distinct Difference Array_test.go b/leetcode/2670/2670. Find the Distinct Difference Array_test.go
new file mode 100644
index 0000000..4385979
--- /dev/null
+++ b/leetcode/2670/2670. Find the Distinct Difference Array_test.go	
@@ -0,0 +1,32 @@
+package _670
+
+import (
+	"reflect"
+	"testing"
+)
+
+func Test_distinctDifferenceArray(t *testing.T) {
+	type args struct {
+		nums []int
+	}
+	tests := []struct {
+		name string
+		args args
+		want []int
+	}{
+		{
+			name: "one",
+			args: args{
+				nums: []int{1, 2, 3, 4, 5},
+			},
+			want: []int{-3, -1, 1, 3, 5},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := distinctDifferenceArray(tt.args.nums); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("distinctDifferenceArray() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}