Help with subtask 1 failing in CHEFWED - AUG20?

here is code : https://www.codechef.com/viewsolution/36859828 (updated link, sorry previous one was wrong link.)

Code
int gettot (vector<int>& F) {
	int ans = 0;
	for (int& i:F) if (i > 1) ans += i;
	return ans;
}


int search (int k, vector<int>& a, vector<int>& F) {
	if (a.size() < 2) return (k * (int)a.size());
	//cout << "Called Search : " << a << '\n';
	int tot = k + gettot(F);
	vi diff(a.size()-1) ;
	vi rightF(101), leftF = F;
	int maxx = 0;
	for (int i = 0; i < a.size() - 1; i++) {
		rightF[a[i]] ++;
		leftF[a[i]] --;
		diff[i] = tot - (k + k + gettot (rightF) + gettot (leftF));
		if (diff[i] > diff[maxx]) maxx = i;
	}
	//cout << "maxx = " << maxx << ' ' << diff[maxx] << '\n';
	//cout << "No futher omptimaztions possible.\n";
	if (diff[maxx] < 0) return tot;
	vi sa(a.begin(), a.begin() + maxx + 1), sb(a.begin() + 1 + maxx, a.end());
	vi Fa(101), Fb(101);
	for (int i = 0; i < a.size(); i++) {
		if (i <= maxx) Fa[a[i]]++;
		else Fb[a[i]]++;
	}
	//cout << "splitted into : " << sa << " and " << sb << '\n';
	return search(k, sa, Fa) + search (k, sb, Fb);
}

void solve() {
	int n, k; cin >> n >> k;
	vi a(n); for (int& i:a) cin >> i;
	vi F(101);
	for (int& i:a) F[i]++;
	cout << search(k, a, F) << '\n';
}

im basically spillting my tables until it is optimal to get more benefit out of it.
but it is failing on subtask 1. ??