Illuminati

# import sys
# from collections import deque, defaultdict, Counter
# from heapq import heappush, heappop, heapify
# from bisect import bisect_left, bisect_right
# from itertools import permutations, combinations, product, accumulate, groupby
# from functools import lru_cache, cmp_to_key, reduce
# from math import gcd, isqrt, comb, inf, pi, sqrt, atan2, hypot



# def main():
#     data = sys.stdin.buffer.read().split(); idx = 0
#     n = int(data[idx]); idx += 1
#     # n, m = map(int, data[idx:idx + 2]); idx += 2
#     # a = list(map(int, data[idx:idx + n])); idx += n
#     # s = data[idx].decode(); idx += 1                  # strings

#     # for _ in range(m):
#     #     a, b = map(int, data[idx:idx + 2]); idx += 2


#     # def multiply(bin_matrix):
#     #     result = [[0 for _ in range(i+1)] for i in range(n)]

#     #     for i in range(n):
#     #         for j in range(i+1):
#     #             # for k in range(n):
#     #             #     # result[i][j] += matrix[i][k] * matrix[k][j]
#     #             #     # result[i][j] += matrix[i][k] * matrix[j][k]
#     #             #     and_val = matrix[i][k] & matrix[j][k]
#     #             #     result[i][j] += and_val.bit_count()

#     #             # for k in range(n):
#     #                 # result[i][j] += matrix[i][k] * matrix[k][j]
#     #                 # result[i][j] += matrix[i][k] * matrix[j][k]
#     #             and_val = bin_matrix[i] & bin_matrix[j]
#     #             result[i][j] = and_val.bit_count()


#     #     return result

#     g = [data[idx + i].decode() for i in range(n)]; idx += n  # grid of n rows, no spaces, strings

#     # matrix = [[int(el) for el in line] for line in g]
#     bin_matrix = [int("0b" + str(line), 2) for line in g]

#     # input = sys.stdin.readline
#     # n, m = map(int, input().split())
#     # s = input().strip()  # strip removes the trailing newline
#     # for line in sys.stdin:  # read until EOF
#     # mt = [[matrix[i][j] for i in range(len(matrix))] for j in range(len(matrix[0]))]
#     # print(mt)
#     out = []
#     # print(matrix)
#     # m2 = multiply(bin_matrix)
#     # m3 = multiply(matrix, m2)
#     # print(m3)



#     total = 0
#     for i in range(n):
#         # total += m3[i][i]
#         b = bin_matrix[i]
#         for k in range(i):
#             # if g[i][k] == "1":
#             if b & (1 << (n-1 -k)) :

#                 and_val = bin_matrix[i] & bin_matrix[k]
#                 total += and_val.bit_count()


#             # total += matrix[i][k] * and_val.bit_count()



#     print(total // 3)
#     # sys.stdout.write("\n".join(map(str, out)) + "\n")  # one value per line
#     # print(*out)                                      # space separated on one line
#     # print(f"{ans:.6f}")                              # float with 6 decimals
#     # print("\n".join("".join(row) for row in g))      # grid of chars


# main()


import sys
from itertools import compress

def main():
    data = sys.stdin.buffer.read().split()
    n = int(data[0]); g = data[1:1 + n]
    # L[i]: neighbors of i that are < i, bit a = vertex a (reversed so bit index == vertex index)
    L = [int(g[i][:i][::-1], 2) if i else 0 for i in range(n)]
    total = 0
    for c in range(n):
        Lc = L[c]
        if Lc:
            nb = compress(range(c), g[c][:c].replace(b'0', b'\x00'))  # neighbors b < c, found in C
            total += sum((Lc & L[b]).bit_count() for b in nb)         # common neighbors a < b
    print(total)

main()

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: ACCEPTED

Test 39

Verdict: ACCEPTED

Test 40

Verdict: ACCEPTED

Test 41

Verdict: ACCEPTED

Test 42

Verdict: ACCEPTED

Test 43

Verdict: ACCEPTED

Test 44

Verdict: ACCEPTED

Test 45

Verdict: ACCEPTED

Test 46

Verdict: ACCEPTED

Test 47

Verdict: ACCEPTED

Test 48

Verdict: ACCEPTED

Test 49

Verdict: ACCEPTED

Test 50

Verdict: ACCEPTED

Test 51

Verdict: ACCEPTED

Test 52

Verdict: TIME LIMIT EXCEEDED

Test 53

Verdict: TIME LIMIT EXCEEDED