EquiLeader

 1         /// <summary>
 2         /// Solution
 3         /// 100/100
 4         /// </summary>
 5         /// <param name="A"></param>
 6         /// <returns></returns>
 7         public static int solution(int[] A)
 8         {
 9             int result = 0;
10             int max = 0;
11             int leader = 0;
12             int leftLeader = 0;
13             int rightLeader = 0;
14 
15             int[] arrLeftLeader = new int[A.Length];
16             int[] arrRightLeader = new int[A.Length];
17             Dictionary<int, int> dic = new Dictionary<int, int>();
18 
19             for (int i = 0; i < A.Length; i++)
20             {
21                 if (!dic.ContainsKey(A[i]))
22                     dic.Add(A[i], 1);
23                 else
24                     dic[A[i]]++;
25 
26                 if (dic[A[i]] > max)
27                 {
28                     max = dic[A[i]];
29                     leader = A[i];
30                 }
31                 if (max > (i + 1) / 2)
32                     arrLeftLeader[i] = leader;
33                 else
34                     arrLeftLeader[i] = -1;
35             }
36 
37             max = 0;
38             dic.Clear();
39 
40             for (int i = A.Length - 1; i >= 0; i--)
41             {
42                 if (!dic.ContainsKey(A[i]))
43                     dic.Add(A[i], 1);
44                 else
45                     dic[A[i]]++;
46 
47                 if (dic[A[i]] > max)
48                 {
49                     max = dic[A[i]];
50                     leader = A[i];
51                 }
52                 if (max > (A.Length - i) / 2)
53                     arrRightLeader[i] = leader;
54                 else
55                     arrRightLeader[i] = -1;
56             }
57 
58             for (int i = 0; i < A.Length - 1; i++)
59             {
60                 leftLeader = arrLeftLeader[i];
61                 rightLeader = arrRightLeader[i + 1];
62                 if (leftLeader != -1 && rightLeader != -1 && leftLeader == rightLeader)
63                     result++;
64             }
65 
66             return result;
67         }