Niitty

input/code.cpp: In function 'bool b(int, int, int)':
input/code.cpp:23:27: warning: comparison of integer expressions of different signedness: 'std::unordered_set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   23 |             if (us.size() == d) {
      |                 ~~~~~~~~~~^~~~

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef vector<int> vi;

#define F first
#define S second
#define PB push_back
#define MP make_pair
#define FOR(i,a,b) for (ll i = a; i < b; i++)

int n=4, d=0;
vector<char> v;
set<vector<int>> s;
unordered_set<char> ds;

bool b(int x, int y, int a) {
    unordered_set<int> us;
    for (int i=0; i<y; i++) {
        for (int j=0; j<x; j++) {
            us.insert(v[a+j+i*n]);
            if (us.size() == d) {
                return true;
            }
        }
    }
    return false;
}

void f(int x, int y, int a) {
    if (x == 0 || y == 0) {
        return;
    }
    else {
        if (b(x, y, a)) {
            if (s.contains({x,y,a})) {
                return;
            }
            s.insert({x,y,a});
        }
        else {
            return;
        }
        f(x-1, y, a+1);
        f(x-1, y, a);
        f(x, y-1, a+n);
        f(x, y-1, a);
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> n;
    for (int i=0; i<n; i++) {
        string x;
        cin >> x;
        for (char c : x) {
            v.push_back(c);
            ds.insert(c);
        }
    }
    d = ds.size();
    if (d==0) {
        cout << ((n*(n+1))/2)*((n*(n+1))/2);
    }
    else {
        f(n, n, 0);
        cout << s.size();
    }

}

Test 1

Group: 1, 2, 3, 4, 5, 6

Verdict: ACCEPTED

Test 2

Group: 1, 2, 3, 4, 5, 6

Verdict: ACCEPTED

Test 3

Group: 1, 2, 3, 4, 5, 6

Verdict: ACCEPTED

Test 4

Group: 1, 2, 3, 4, 5, 6

Verdict: ACCEPTED

Test 5

Group: 1, 2, 3, 4, 5, 6

Verdict: ACCEPTED

Test 6

Group: 2, 3, 4, 5, 6

Verdict: ACCEPTED

Test 7

Group: 2, 3, 4, 5, 6

Verdict: ACCEPTED

Test 8

Group: 2, 3, 4, 5, 6

Verdict: ACCEPTED

Test 9

Group: 2, 3, 4, 5, 6

Verdict: ACCEPTED

Test 10

Group: 3, 4, 5, 6

Verdict: TIME LIMIT EXCEEDED

Test 11

Group: 3, 4, 5, 6

Verdict: TIME LIMIT EXCEEDED

Test 12

Group: 3, 4, 5, 6

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 3, 4, 5, 6

Verdict: ACCEPTED

Test 14

Group: 4, 5, 6

Verdict: TIME LIMIT EXCEEDED

Test 15

Group: 4, 5, 6

Verdict: TIME LIMIT EXCEEDED

Test 16

Group: 4, 5, 6

Verdict: TIME LIMIT EXCEEDED

Test 17

Group: 4, 5, 6

Verdict: TIME LIMIT EXCEEDED

Test 18

Group: 5, 6

Verdict: TIME LIMIT EXCEEDED

Test 19

Group: 5, 6

Verdict: TIME LIMIT EXCEEDED

Test 20

Group: 5, 6

Verdict: TIME LIMIT EXCEEDED

Test 21

Group: 5, 6

Verdict: TIME LIMIT EXCEEDED

Test 22

Group: 6

Verdict: TIME LIMIT EXCEEDED

Test 23

Group: 6

Verdict: TIME LIMIT EXCEEDED

Test 24

Group: 6

Verdict: TIME LIMIT EXCEEDED

Test 25

Group: 6

Verdict: TIME LIMIT EXCEEDED