18. 4Sum

18. 4Sum/Program.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+var sol = new Solution();
+
+var cases = new (int[] nums, int target, int[][] expected)[]
+{
+	// (new[] { 1, 0, -1, 0, -2, 2 }, 0, new[]
+	// {
+	// 	new[] { -2, -1, 1, 2 },
+	// 	new[] { -2, 0, 0, 2 },
+	// 	new[] { -1, 0, 0, 1 }
+	// }),
+	// (new[] { 2, 2, 2, 2, 2 }, 8, new[]
+	// {
+	// 	new[] { 2, 2, 2, 2 }
+	// }),
+	// (new[] { -3, -1, 0, 2, 4, 5 }, 2, new[]
+	// {
+	// 	new[] { -3, -1, 2, 4 }
+	// }),
+	(new[] { 1000000000, 1000000000, 1000000000, 1000000000 }, -294967296, Array.Empty<int[]>())
+};
+
+foreach (var (nums, target, expected) in cases)
+{
+	var actual = sol.FourSum(nums, target);
+	Console.WriteLine($"nums={FormatArray(nums)}, target={target} -> {FormatResults(actual)} (expected: {FormatResults(expected)})");
+}
+
+static string FormatArray(int[] nums)
+{
+	return $"[{string.Join(",", nums)}]";
+}
+
+static string FormatResults(IList<IList<int>> results)
+{
+	return "[" + string.Join(",", results.Select(r => $"[{string.Join(",", r)}]")) + "]";
+}