Illuminati

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

typedef unsigned long long ull;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    
    int n;
    cin >> n;
    int word_cnt = (n + 63) / 64;
    vector<ull> adj(n * word_cnt, 0ULL);
    
    for(int i = 0; i < n; i++){
        string s;
        cin >> s;
        for(int j = 0; j < n; j++){
            // Ensure no self-loops are counted
            if(j != i && s[j] == '1'){
                int w = j / 64;
                int b = j % 64;
                adj[i * word_cnt + w] |= (1ULL << b);
            }
        }
    }
    
    unsigned long long count = 0;
    for(int u = 0; u < n; u++){
        int word_u = u / 64;
        int bit_u = u % 64;
        for(int w_idx = word_u; w_idx < word_cnt; w_idx++){
            ull mask;
            if(w_idx == word_u){
                mask = (~0ULL) << (bit_u + 1);
            }
            else{
                mask = ~0ULL;
            }
            // Handle the last word if n is not a multiple of 64
            if(w_idx == word_cnt - 1 && (n % 64) != 0){
                mask &= (1ULL << (n % 64)) - 1;
            }
            ull w = adj[u * word_cnt + w_idx] & mask;
            while(w){
                ull lsb = w & -w;
                int pos = __builtin_ctzll(w);
                int v = w_idx * 64 + pos;
                if(v >= n) break;
                // Compute popcount of A[u] & A[v]
                unsigned int tmp_count = 0;
                for(int m = 0; m < word_cnt; m++){
                    tmp_count += __builtin_popcountll(adj[u * word_cnt + m] & adj[v * word_cnt + m]);
                }
                count += tmp_count;
                w ^= lsb;
            }
        }
    }
    // Each triangle is counted three times
    cout << (count / 3) << "\n";
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED

Test 29

Verdict: ACCEPTED

Test 30

Verdict: ACCEPTED

Test 31

Verdict: ACCEPTED

Test 32

Verdict: ACCEPTED

Test 33

Verdict: ACCEPTED

Test 34

Verdict: ACCEPTED

Test 35

Verdict: ACCEPTED

Test 36

Verdict: ACCEPTED

Test 37

Verdict: ACCEPTED

Test 38

Verdict: WRONG ANSWER

Test 39

Verdict: WRONG ANSWER

Test 40

Verdict: WRONG ANSWER

Test 41

Verdict: WRONG ANSWER

Test 42

Verdict: WRONG ANSWER

Test 43

Verdict: WRONG ANSWER

Test 44

Verdict: WRONG ANSWER

Test 45

Verdict: WRONG ANSWER

Test 46

Verdict: WRONG ANSWER

Test 47

Verdict: WRONG ANSWER

Test 48

Verdict: WRONG ANSWER

Test 49

Verdict: WRONG ANSWER

Test 50

Verdict: WRONG ANSWER

Test 51

Verdict: WRONG ANSWER

Test 52

Verdict: WRONG ANSWER

Test 53

Verdict: WRONG ANSWER