Problem: There are N towns numbered 1 to N and M roads. The i-th road connects Town A_i and Town B_i bidirectionally and has a length of C_i.  Takahashi will travel between these towns by car, passing through these roads. The fuel tank of his car can contain at most L liters of fuel, and one liter of fuel is consumed for each unit distance traveled. When visiting a town while traveling, he can full the tank (or choose not to do so). Travel that results in the tank becoming empty halfway on the road cannot be done.  Process the following Q queries:    * The tank is now full. Find the minimum number of times he needs to full his tank while traveling from Town s_i to Town t_i. If Town t_i is unreachable, print -1.

Submission attempts (in order):
from scipy.sparse import csr_matrix 
from scipy.sparse.csgraph import shortest_path, floyd_warshall
import numpy as np

import sys
def input():
	return sys.stdin.readline().strip()

N, M, L = list(map(int, input().split()))

A = np.zeros(M)
B = np.zeros(M)
C = np.zeros(M)
for i in range(M):
	Ai, Bi, Ci = list(map(int, input().split()))
	A[i] = Ai - 1
	B[i] = Bi - 1
	C[i] = Ci

graph = csr_matrix((C, (A, B)), shape=(N, N))
#print(graph)
dist = floyd_warshall(graph, directed=False)

graph2 = np.full((N, N), np.inf)
graph2[dist <= L] = 1
graph2 = csr_matrix(graph2)
num = floyd_warshall(graph2, directed=False)


Q = int(input())
for q in range(Q):
	s, t = list(map(int, input().split()))
	if num[s - 1][t - 1] < 10000000:
		continue

from scipy.sparse import csr_matrix 
from scipy.sparse.csgraph import shortest_path, floyd_warshall
import numpy as np

import sys
def input():
	return sys.stdin.readline().strip()

N, M, L = list(map(int, input().split()))

A = np.zeros(M)
B = np.zeros(M)
C = np.zeros(M)
for i in range(M):
	Ai, Bi, Ci = list(map(int, input().split()))
	A[i] = Ai - 1
	B[i] = Bi - 1
	C[i] = Ci

graph = csr_matrix((C, (A, B)), shape=(N, N))
#print(graph)
dist = floyd_warshall(graph, directed=False)

graph2 = np.full((N, N), np.inf)
graph2[dist <= L] = 1
graph2 = csr_matrix(graph2)
num = floyd_warshall(graph2, directed=False)




from scipy.sparse import csr_matrix 
from scipy.sparse.csgraph import shortest_path, floyd_warshall
import numpy as np

import sys
def input():
	return sys.stdin.readline().strip()

N, M, L = list(map(int, input().split()))

A = np.zeros(M)
B = np.zeros(M)
C = np.zeros(M)
for i in range(M):
	Ai, Bi, Ci = list(map(int, input().split()))
	A[i] = Ai - 1
	B[i] = Bi - 1
	C[i] = Ci

graph = csr_matrix((C, (A, B)), shape=(N, N))
#print(graph)
dist = floyd_warshall(graph, directed=False)

graph2 = np.full((N, N), np.inf)
graph2[dist <= L] = 1
graph2 = csr_matrix(graph2)
num = floyd_warshall(graph2, directed=False)


Q = int(input())
for q in range(Q):
	s, t = list(map(int, input().split()))



from scipy.sparse import csr_matrix 
from scipy.sparse.csgraph import shortest_path, floyd_warshall
import numpy as np

import sys
def input():
	return sys.stdin.readline().strip()

N, M, L = list(map(int, input().split()))

A = [0]*M
B = [0]*M
C = [0]*M
for i in range(M):
	Ai, Bi, Ci = list(map(int, input().split()))
	A[i] = Ai - 1
	B[i] = Bi - 1
	C[i] = Ci

graph = csr_matrix((C, (A, B)), shape=(N, N))
#print(graph)
dist = floyd_warshall(graph, directed=False)

graph2 = np.full((N, N), np.inf)
graph2[dist <= L] = 1
graph2 = csr_matrix(graph2)
num = floyd_warshall(graph2, directed=False)


num = num.tolist()

Q = int(input())
for q in range(Q):
	s, t = list(map(int, input().split()))
	if num[s - 1][t - 1] < 10000000:
		print(int(num[s - 1][t - 1] - 1))
	else:
		print(-1)

Verdicts: Wrong Answer

Wrong Answer

Wrong Answer

Accepted