Merkkijonot

input/code.cpp: In function 'll haku(ll, ll, ll)':
input/code.cpp:16:10: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |     if(k == v.size() && as == ya && bs == yb) return 1;
      |        ~~^~~~~~~~~~~
input/code.cpp:17:10: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |     if(k >= v.size() || as > ya || bs > yb) return 0;
      |        ~~^~~~~~~~~~~
input/code.cpp: In function 'int main()':
input/code.cpp:35:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |         for(int j = 0; j < s.length(); j++){
      |...

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

typedef long long ll;

int n;
ll ya, yb; 
vector<pair<ll,ll>> v;
ll mod;
vector<vector<vector<ll>>> d;

ll haku(ll k, ll as, ll bs){
    if(k == v.size() && as == ya && bs == yb) return 1;
    if(k >= v.size() || as > ya || bs > yb) return 0;
    if(d[k][as][bs]) return d[k][as][bs];
    ll u = (haku(k + 1, as, bs) + haku(k + 1, as + v[k].first, bs + v[k].second)) % mod;
    //cout << k << " " << as << " " << bs << "\n";
    d[k][as][bs] = u; 
    return u;
}

int main(){
    cin >> n;
    mod = 1e9 - 7;
    ya = 0; 
    yb = 0;
    d.resize(n);
    for(int i = 0; i < n; i++){
        int a = 0; int b = 0;
        string s;
        cin >> s;
        for(int j = 0; j < s.length(); j++){
            if(s[j] == 'a') a++; 
            else b++; 
        }
        v.push_back({a, b});
        ya += a;
        yb += b;
    }
    if(ya % 2 == 1 || yb % 2 == 1){
        cout << 0;
        return 0; 
    }
    ya /= 2;
    yb /= 2;

    //cout << n << " " << ya << " " << yb << "\n";
    
    for(int i = 0; i < n; i++){
        d[i].resize(ya + 1);
        for(int j = 0; j <= ya; j++) d[i][j].resize(yb + 1);
    }

    sort(v.begin(), v.end());
    cout << (haku(0, 0, 0)) % mod;
    
}

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: 2, 3

Verdict: ACCEPTED

Test 7

Group: 2, 3

Verdict: ACCEPTED

Test 8

Group: 2, 3

Verdict: TIME LIMIT EXCEEDED

Test 9

Group: 3

Verdict: ACCEPTED

Test 10

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 11

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 12

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 2, 3

Verdict: TIME LIMIT EXCEEDED

Test 16

Group: 3

Verdict: TIME LIMIT EXCEEDED