CF958F2 Lightsabers (medium)

CI N = 2e5 + 5;
int n, m, ans = 1e9, cnt, sum, a[N], b[N], v[N];
signed main() {
	n = read(), m = read();
	arrin(a, n);
	arrin(b, m);
	rep(i, 1, m) if(!b[i]) cnt ++;
	for(int i = 1, j = 0; i <= n; i ++) {
		while(cnt < m && j < n || j < i) j ++, cnt += ++v[a[j]] == b[a[j]], sum += v[a[j]] > b[a[j]];
		if(cnt == m) ans = std::min(ans, sum);
		cnt -= --v[a[i]] < b[a[i]], sum -= v[a[i]] >= b[a[i]];
	}
	print(ans == 1e9 ? -1 : ans);
	return 0;
}