Python

n=3 adjacency_matrix =[ [2, 3, 0] , [0, 0, 1] , [1, 5, 0] ] li_r = [] li_c = [] for i in range(n): for j in range(n): if adjacency_matrix[i][j]!=0: li_r.append(i) li_c.append(j) print(li_r) print(li_c)

You may also use the more concise, but less efficient

Python

n=3 adjacency_matrix =[ [2, 3, 0] , [0, 0, 1] , [1, 5, 0] ] li_r = [r for r in range(n) for c in range(n) if adjacency_matrix[r][c] != 0] li_c = [c for r in range(n) for c in range(n) if adjacency_matrix[r][c] != 0] print(li_r) print(li_c)