1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
|
import std.stdio:writeln;
import std.algorithm:all,filter,reduce,uniq,minElement,sort;
import std.array:array;
int most_frequent_even(int[] arr)
{
if(all!"a & 1"(arr)) return -1;
int[int] hash;
foreach(int i; filter!(a => !(a & 1))(arr)) if(!(i & 1)) hash[i]++;
if(hash.values.length == hash.values.uniq.array.length)
return hash.keys.minElement;
return reduce!((a,b) => hash[a] == hash[b] ? a : b)(hash.keys.sort);
}
void main()
{
int[] a1 = [1,1,2,6,2];
int[] a2 = [1,3,5,7];
int[] a3 = [6,4,4,6,1];
writeln(most_frequent_even(a1));
writeln(most_frequent_even(a2));
writeln(most_frequent_even(a3));
}
|
