Ositus

input/code.cpp: In function 'int main()':
input/code.cpp:49:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (ll i = 0; i < s.size(); i++)
                 ~~^~~~~~~~~~
input/code.cpp:55:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (ll j = 1; j < i.second.size(); j++)
                   ~~^~~~~~~~~~~~~~~~~

using namespace std;
#include <iostream>
#include <vector>
#include <map>
#include <algorithm>
#define ll long long

ll M = 1e9 + 7, N = 0, x = 0;
map<char, vector<ll>> m;
vector<pair<ll, ll>> v;
vector<ll> u;

void haku(ll k)
{
	if (k == N + 1)
	{
		bool b1 = true;
		for (auto i : v)
		{
			bool b2 = false;
			for (ll j = i.first; j <= i.second; j++)
			{
				if (find(u.begin(), u.end(), j) != u.end())
				{
					b2 = true; break;
				}
			}
			if (!b2)
			{
				b1 = false; break;
			}
		}
		if (b1)x = (x + 1) % M;
	}
	else
	{
		haku(k + 1);
		u.push_back(k);
		haku(k + 1);
		u.pop_back();
	}
}

int main()
{
	string s;
	cin >> s;
	N = s.size() - 1;
	for (ll i = 0; i < s.size(); i++)
		m[s[i]].push_back(i);
	for (auto i : m)
	{
		if (i.second.size() > 1)
		{
			for (ll j = 1; j < i.second.size(); j++)
				v.push_back({ i.second[j - 1] + 1, i.second[j]});
		}
	}
	haku(1);
	cout << x;
}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 1, 2, 3

Verdict: ACCEPTED

Test 3

Group: 1, 2, 3

Verdict: ACCEPTED

Test 4

Group: 1, 2, 3

Verdict: ACCEPTED

Test 5

Group: 2, 3

Verdict: TIME LIMIT EXCEEDED

Test 6

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 7

Group: 3

Verdict: TIME LIMIT EXCEEDED