萌新的程序死活过不了样例，一直输出8……

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cmath>
#include<cstring>

using namespace std;

const int N = 1e5 + 10;
const int M = 21;

int n, m, a[N], sum[M][N], t[M], f[1 << M];
int main(void) {

	ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);

	cin >> n >> m;

	for (int i = 1; i <= n; ++i) {
		cin >> a[i];
		t[a[i]] ++;
		sum[a[i]][i] ++;
	}

	for (int i = 1; i <= m; ++i) {
		for (int j = 1; j <= n; ++j) {
			sum[i][j] = sum[i][j] + sum[i][j - 1];
		}
	//cout << sum[i][n] << endl;
	}

	memset(f, 0x3f, sizeof(f));

	f[0] = 0;

	for (int i = 0; i < (1 << m); ++i) {
		int s = 0;
		for (int j = 1; j <= m; ++j) {
			if (i & (1 << (j - 1))) {
				s += t[j];
			}
		}
		for (int j = 1; j <= m; ++j) {
			if (i & (1 << (j - 1)))
				continue;
			int L = s - t[j], R = s;
			f[i | (1 << (j - 1))] = min(f[i | (1 << (j - 1))], f[i] + (R - L) - (sum[j][R] - sum[j][L]));
		}
	}

	cout << f[(1 << m) - 1] << endl;

	return 0;

}