Ositus

input/code.cpp: In function 'void partitioning(std::__cxx11::string)':
input/code.cpp:18:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 1; i < s.length(); i++) {
                     ~~^~~~~~~~~~~~

/**
 * Datatähti 2022 alku
 * Ositus (Partitioning)
 * @author TRS
 */
#include <bits/stdc++.h>
using namespace std;
//Constants
#define infinity 0x3f3f3f3f
#define linfinity 0x3f3f3f3f3f3f3f3f
#define MOD 1000000007
const int MX = 1000001;
long long partitions[MX];
int appeared;
void partitioning(string s) {
    s = "." + s;
    partitions[0] = 1;
    for (int i = 1; i < s.length(); i++) {
        appeared = 0;
        for (int j = i; j > 0; j--) {
            if (appeared & (1 << (s.at(j) - 'a'))) {
                break;
            }
            appeared |= (1 << (s.at(j) - 'a'));
            partitions[i] += partitions[j - 1];
            partitions[i] %= MOD;
        }
    }
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    string s;
    getline(cin, s);
    if (s.length() == 1) {
        cout<<1<<"\n";
        return 0;
    }
    partitioning(s);
    cout<<partitions[s.length()]<<"\n";
    return 0;
}

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: ACCEPTED

Test 6

Group: 3

Verdict: ACCEPTED

Test 7

Group: 3

Verdict: ACCEPTED