import numpy as np
from scipy.sparse import csr_matrix

n = 5  # number of nodes
adj_list = [[1, 3], [0, 2, 3], [1, 4], [0, 1], []]

# Create the row and column indices arrays
rows = []
cols = []
for i in range(n):
    for j in adj_list[i]:
        rows.append(i)
        cols.append(j)

# Create the data array (all ones for unweighted graph)
data = np.ones(len(rows))

# Create the CSR matrix
csr_mat = csr_matrix((data, (rows, cols)), shape=(n, n))