1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
#include <cstdio>

using namespace std;

class Tree
{
private:
	int n;
	int* p;
	int* key;
	int* left;
	int* right;


public:
	int End;
	int Root;
	int height;

	Tree(int N) {
		n = N;

		left = new int[n];
		right = new int[n];
		key = new int[n];
		p = new int[n];

		Root = -1;
		End = 0;
	}

	~Tree() {
		//delete[] left;
		//delete[] right;
		//delete[] key;
		//delete[] p;
	}

	int Insertion(int el) {
		int z = -1;
		//preparing end element
			if (End <= n)
			{
				key[End] = el;
				p[End] = -1;
				left[End] = -1;
				right[End] = -1;
				z = End;

				End++;
			}
			else {
				return 6;
			}

			int x = Root;
			int y = -1;
			int k = key[z];
			int i = 0;

			while (x != -1) // look for father 
			{
				y = x;
				if (k < key[y])
					x = left[y];
				else
					x = right[y];
				i++;
			}

			if (i > height)
				height = i;

			p[z] = y; // y is father

			if (y == -1)
				Root = z; //if tree was empty
			else
			{
				if (k < key[y])
					left[y] = z;
				else
					right[y] = z;
			}

		return 0;
	}

	bool Member(int x)
	{
		int i = Root;

		while (i != -1)
		{
			if (x < key[i])
				i = left[i];
			else if (x == key[i])
				return true;
			else
				i = right[i];
		}
		return false;
	}
};

int main()
{
	int n = -1;
	int k = -1;

	int d = 0; // desire position
	int ac = 0; // actual position
	bool first = true;

	int swaps = 0;

	scanf("%d %d", &n, &k);

	Tree t(n);
	Tree t2(n);
	int el = 0;

	for (int i = 0; i < n && t.End <= k; i++)
	{
		scanf("%d", &el);

		ac = t2.End;
		t2.Insertion(el);

		if (!t.Member(el))
		{
			d = t.End;
			t.Insertion(el);
			swaps = swaps + (ac - d);
		}
	}

	if (t.End < k)
		printf("-1");
	else
		printf("%d", swaps);

	return 0;
}