class Program { static void Main(string[] args) { int[] input = { 1, 1, 1, 2, 2, 5, 2, 4, 9, 9, 20 }; IDuplicationFinder dup1 = new Duplication1(); string str1 = dup1.FindDuplication(input, 3); Console.WriteLine(str1); IDuplicationFinder dup2 = new Duplication2(); string str2 = dup2.FindDuplication(input, 3); Console.WriteLine(str2); Console.Read(); } } class Duplication1 : IDuplicationFinder { public string FindDuplication(int[] input, uint minTimes) { Dictionary<int, int> valuedic = new Dictionary<int, int>(); #region 整个完全遍历 //foreach (var v in input) //{ // var numtimes = input.Where(m => m == v).Count(); // if (numtimes >= minTimes && !valuedic.Keys.Contains(v)) // valuedic.Add(v, numtimes); //} #endregion #region linq group var groupnum = input.GroupBy(m => m); foreach (var g in groupnum) { if (g.Count() >= minTimes) valuedic.Add(g.Key, g.Count()); } #endregion return GetValue(valuedic); } private static string GetValue(Dictionary<int, int> valuedic) { StringBuilder sb = new StringBuilder(); foreach (var d in valuedic) { sb.AppendFormat("{0}出现了{1}次", d.Key, d.Value); sb.AppendLine(); } return sb.ToString(); } } class Duplication2 : IDuplicationFinder { public string FindDuplication(int[] input, uint minTimes) { List<int> result = new List<int>(); Array.Sort(input); if (minTimes == 1)//如果次数是1,就要把去重显示 { if (input[0] == input[1]) result.Add(input[1]); for (int i = 1; i < input.Length - 1; i++) { if (input[i] != input[i + 1]) result.Add(input[i + 1]); } } else { int count = 1;//排序后 前一个跟后一个对比,所以从1开始 for (int i = 0; i < input.Length - 1; i++) { if (result.Count > 0 && result.Last() == input[i]) continue; if (input[i] == input[i + 1]) { count++; if (count >= minTimes) { result.Add(input[i]); count = 1; } } } } return string.Join(",", result); } } interface IDuplicationFinder { string FindDuplication(int[] input, uint minTimes); }
t=[1,22,33,1,44,22,11,3,224,5,6,22,1,44]//查找出现次数最多的数字和次数 ruby hst={} t.each do |item| if(hst.key?(item)) hst[item]+=1 else hst[item]=1 end end p hst b = Hash[hst.sort_by(){ |k, v| v }.reverse] p b p b.first