Problem:


Score : 500 points

Problem Statement

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.

Constraints

All values in input are integers.

2 \leq N \leq 300

0 \leq M \leq \frac{N(N-1)}{2}

1 \leq L \leq 10^9

1 \leq A_i, B_i \leq N

A_i \neq B_i

\left(A_i, B_i\right) \neq \left(A_j, B_j\right) (if i \neq j)

\left(A_i, B_i\right) \neq \left(B_j, A_j\right) (if i \neq j)

1 \leq C_i \leq 10^9

1 \leq Q \leq N\left(N-1\right)

1 \leq s_i, t_i \leq N

s_i \neq t_i

\left(s_i, t_i\right) \neq \left(s_j, t_j\right) (if i \neq j)

Input

Input is given from Standard Input in the following format:

N M L
A_1 B_1 C_1
:
A_M B_M C_M
Q
s_1 t_1
:
s_Q t_Q

Output

Print Q lines.

The i-th line should contain the minimum number of times the tank needs to be fulled while traveling from Town s_i to Town t_i. If Town t_i is unreachable, the line should contain -1 instead.

Sample Input 1

3 2 5
1 2 3
2 3 3
2
3 2
1 3

Sample Output 1

0
1

To travel from Town 3 to Town 2, we can use the second road to reach Town 2 without fueling the tank on the way.

To travel from Town 1 to Town 3, we can first use the first road to get to Town 2, full the tank, and use the second road to reach Town 3.

Sample Input 2

4 0 1
1
2 1

Sample Output 2

-1

There may be no road at all.

Sample Input 3

5 4 4
1 2 2
2 3 2
3 4 3
4 5 2
20
2 1
3 1
4 1
5 1
1 2
3 2
4 2
5 2
1 3
2 3
4 3
5 3
1 4
2 4
3 4
5 4
1 5
2 5
3 5
4 5

Sample Output 3

0
0
1
2
0
0
1
2
0
0
0
1
1
1
0
0
2
2
1
0



Sample input:
3 2 5
1 2 3
2 3 3
2
3 2
1 3


Sample output:
0
1

Submission status: Accepted

Solution code:
from scipy.sparse.csgraph import floyd_warshall
import numpy as np
 
N, M, L = map(int, input().split())
graph = np.full((N, N), 10**10)
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1][t-1] = graph[t-1][s-1] = w
graph = floyd_warshall(graph, directed=False)
graph = floyd_warshall(graph <= L, directed=False)
graph[np.isinf(graph)] = 0
 
Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(int(graph[s-1][t-1]) - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def use_fast_io():
    global input
    import io
    import sys
    f = io.BytesIO(sys.stdin.buffer.read())
    input = f.readline
use_fast_io()
 
 
from scipy.sparse.csgraph import floyd_warshall
import numpy as np
 
N, M, L = map(int, input().split())
graph = np.full((N, N), 10**10)
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1][t-1] = graph[t-1][s-1] = w
graph = floyd_warshall(graph, directed=False)
graph = floyd_warshall(graph <= L, directed=False)
graph[np.isinf(graph)] = 0
 
Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(int(graph[s-1][t-1]) - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:

from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = np.full((N, N), 10 ** 10)
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s - 1][t - 1] = graph[t - 1][s - 1] = w
graph = floyd_warshall(graph, directed=False)
graph = floyd_warshall(graph <= L, directed=False)
graph[np.isinf(graph)] = 0

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(int(graph[s - 1][t - 1]) - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
from scipy.sparse import*
i=lambda:tuple(map(int,input().split()))
f=csgraph.dijkstra
n,m,l=i()
d=eval('[0]*-~n,'*-~n)
while m:a,b,c=i();d[a][b]=c;m-=1
d=f(f(d,0)<=l)-1
d[d>n]=-1
for _ in'_'*i()[0]:print(d[i()])

Submission status: Accepted

Solution code:
from scipy.sparse import*
i=lambda:tuple(map(int,input().split()))
f=csgraph.dijkstra
n,m,l=i()
d=eval('[0]*-~n,'*-~n)
while m:a,b,c=i();d[a][b]=c;m-=1
d=f(f(d,0)<=l)
d[d>n]=0
for _ in'_'*i()[0]:print(int(d[i()])-1)

Submission status: Accepted

Solution code:
import sys
from scipy.sparse import csr_matrix
from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, sys.stdin.buffer.readline().split())
rest = np.array(sys.stdin.buffer.read().split(), np.int)
in_, out, weight = rest[0:3*M:3], rest[1:3*M:3], rest[2:3*M:3]

graph = csr_matrix((weight, (in_, out)), shape=(N+1, N+1))
graph = floyd_warshall(graph, directed=False)
graph = floyd_warshall(graph <= L, directed=False)
graph[np.isinf(graph)] = 0

S, T = rest[3*M+1::2], rest[3*M+2::2]
print('\n'.join(map(str, graph[S, T].astype(int) - 1)))

Submission status: Accepted

Solution code:
import sys
from collections import defaultdict
from scipy.sparse.csgraph import floyd_warshall
from scipy.sparse import csr_matrix
import numpy as np

def solve(N: int, M: int, L: int, A: "List[int]", B: "List[int]", C: "List[int]", Q: int, s: "List[int]", t: "List[int]"):
    distance = [[0 for i in range(N)] for _ in range(N)] ## nかけるn
    for abc in zip(A,B,C):
        distance[abc[0]-1][abc[1]-1] = abc[2]
        distance[abc[1]-1][abc[0]-1] = abc[2]
    graph = csr_matrix(distance)
    dist_matrix = floyd_warshall(graph,directed=False) ## 最短経路の行列
    
    fuel_matrix = [[0 for i in range(N)] for _ in range(N)] ## nかけるn
    for i in range(N):
      for j in range(N):
        if 0 < dist_matrix[i][j] <= L:
          fuel_matrix[i][j] = 1
    graph2 = csr_matrix(fuel_matrix)
    dist_matrix2 = floyd_warshall(graph2,directed=False) ## 最短経路の行列

    for i in range(Q):
      if dist_matrix2[s[i]-1][t[i]-1] == float("inf"):
        print(-1)
      else:
        print(int(dist_matrix2[s[i]-1][t[i]-1])-1)
                
    return

def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    M = int(next(tokens))  # type: int
    L = int(next(tokens))  # type: int
    A = [int()] * (M)  # type: "List[int]"
    B = [int()] * (M)  # type: "List[int]"
    C = [int()] * (M)  # type: "List[int]"
    for i in range(M):
        A[i] = int(next(tokens))
        B[i] = int(next(tokens))
        C[i] = int(next(tokens))
    Q = int(next(tokens))  # type: int
    s = [int()] * (Q)  # type: "List[int]"
    t = [int()] * (Q)  # type: "List[int]"
    for i in range(Q):
        s[i] = int(next(tokens))
        t[i] = int(next(tokens))
    solve(N, M, L, A, B, C, Q, s, t)

if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
import sys
from scipy.sparse import csr_matrix
from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, sys.stdin.buffer.readline().split())
rest = np.array(sys.stdin.buffer.read().split(), np.int)
in_, out, weight = rest[0:3*M:3], rest[1:3*M:3], rest[2:3*M:3]

graph = csr_matrix((weight, (in_, out)), shape=(N+1, N+1))
graph = floyd_warshall(graph, directed=False)
graph = floyd_warshall(graph <= L, directed=False)
graph[np.isinf(graph)] = 0

S, T = rest[3*M+1::2], rest[3*M+2::2]
print(*(graph[S, T].astype(int) - 1), sep='\n')

Submission status: Accepted

Solution code:
import sys
from scipy.sparse import csr_matrix
from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L, *rest = map(int, sys.stdin.buffer.read().split())
in_, out, weight = rest[0:3*M:3], rest[1:3*M:3], rest[2:3*M:3]

graph = csr_matrix((weight, (in_, out)), shape=(N+1, N+1))
graph = floyd_warshall(graph, directed=False)
graph = floyd_warshall(graph <= L, directed=False)
graph[np.isinf(graph)] = 0

S, T = rest[3*M+1::2], rest[3*M+2::2]
print(*(graph[S, T] - 1).astype(int), sep='\n')

Submission status: Accepted

Solution code:
def use_fast_io():
    global input
    import io
    import sys
    f = io.BytesIO(sys.stdin.buffer.read())
    input = f.readline
use_fast_io()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = [[10**10] * N for _ in range(N)]
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1][t-1] = graph[t-1][s-1] = w
graph = floyd_warshall(graph, directed=False)
graph = floyd_warshall(graph <= L, directed=False)
graph[np.isinf(graph)] = 0

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(int(graph[s-1][t-1]) - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def use_fast_io():
    global input
    import io
    import sys
    f = io.BytesIO(sys.stdin.buffer.read())
    input = f.readline
use_fast_io()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = np.full((N, N), 10**10)
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1][t-1] = graph[t-1][s-1] = w
graph = floyd_warshall(graph, directed=False)
graph = floyd_warshall(graph <= L, directed=False)
graph[np.isinf(graph)] = 0

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(int(graph[s-1][t-1]) - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
from scipy.sparse import*
i=lambda:tuple(map(int,input().split()))
f=csgraph.floyd_warshall
n,m,l=i()
d=eval('[0]*-~n,'*-~n)
exec('a,b,c=i();d[a][b]=c;'*m)
d=f(f(d,0)<=l)
d[d>n]=0
for _ in'_'*i()[0]:print(int(d[i()])-1)

Submission status: Accepted

Solution code:
def use_fast_io():
    global input
    import io
    import sys
    f = io.BytesIO(sys.stdin.buffer.read())
    input = f.readline
use_fast_io()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = np.full((N, N), np.inf)
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1][t-1] = graph[t-1][s-1] = w
graph = floyd_warshall(graph, directed=False)
graph = floyd_warshall(graph <= L, directed=False)
graph[np.isinf(graph)] = 0

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(int(graph[s-1][t-1]) - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def use_fast_io():
    global input
    import io
    import sys
    f = io.BytesIO(sys.stdin.buffer.read())
    input = f.readline
use_fast_io()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = [[float("inf")] * N for _ in range(N)]
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1][t-1] = graph[t-1][s-1] = w
graph = floyd_warshall(graph, directed=False)
graph = floyd_warshall(graph <= L, directed=False)
graph[np.isinf(graph)] = 0

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(int(graph[s-1][t-1]) - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def use_fast_io():
    global input
    import io
    import sys
    f = io.BytesIO(sys.stdin.buffer.read())
    input = f.readline
use_fast_io()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = [[0] * N for _ in range(N)]
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1][t-1] = graph[t-1][s-1] = w
graph = floyd_warshall(graph, directed=False)
graph = floyd_warshall(graph <= L, directed=False)
graph[np.isinf(graph)] = 0

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(int(graph[s-1][t-1]) - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def use_fast_io():
    global input
    import io
    import sys
    f = io.BytesIO(sys.stdin.buffer.read())
    input = f.readline
use_fast_io()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = np.zeros((N, N), dtype=int)
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1, t-1] = graph[t-1, s-1] = w
graph = floyd_warshall(graph, directed=False)
graph = floyd_warshall(graph <= L, directed=False)
graph[np.isinf(graph)] = 0

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(int(graph[s-1][t-1]) - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
from scipy.sparse import*
i=lambda:tuple(map(int,input().split()))
f=csgraph.floyd_warshall
n,m,l=i()
d=eval('[0]*-~n,'*-~n)
exec('a,b,c=i();d[a][b]=c;'*m)
d=f(f(d,0)<=l)
d[d>9e9]=0
for _ in'_'*i()[0]:print(int(d[i()])-1)

Submission status: Accepted

Solution code:
from scipy.sparse import*
i=lambda:map(int,input().split())
f=csgraph.floyd_warshall
n,m,l=i()
d=eval('[0]*-~n,'*-~n)
exec('a,b,c=i();d[a][b]=c;'*m)
d=f(f(d,0)<=l)
d[d>9e9]=0
q,=i()
while q:s,t=i();print(int(d[s,t])-1);q-=1

Submission status: Accepted

Solution code:
def io_tmp():
    global input
    import io, sys
    f = io.BytesIO(sys.stdin.buffer.read())
    input = f.readline

io_tmp()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = np.zeros((N, N))
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1, t-1] = graph[t-1, s-1] = w
floyd_warshall(graph, directed=False, overwrite=True)
dist = floyd_warshall(graph <= L, directed=False)
dist[np.isinf(dist)] = 0.0

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(int(dist[s-1][t-1]) - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
from scipy.sparse import*
i=lambda:map(int,input().split())
f=csgraph.floyd_warshall
I=9e9
n,m,l=i()
d=eval('[I]*-~n,'*-~n)
exec('a,b,c=i();d[a][b]=c;'*m)
d=f(f(d,0)<=l)
d[d>I]=I
q,=i()
while q:s,t=i();print(int(d[s,t]%I)-1);q-=1

Submission status: Accepted

Solution code:
def io_tmp():
    global input
    import io, sys
    f = io.BytesIO(sys.stdin.buffer.read())
    input = f.readline

io_tmp()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = np.zeros((N, N))
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1, t-1] = graph[t-1, s-1] = w
dist = floyd_warshall(graph, directed=False)
dist = floyd_warshall(dist <= L, directed=False)
dist[np.isinf(dist)] = 0.0

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(int(dist[s-1][t-1]) - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def use_fast_io():
    global input
    import io, sys
    f = io.BytesIO(sys.stdin.buffer.read())
    input = f.readline

use_fast_io()


from scipy.sparse.csgraph import floyd_warshall

N, M, L = map(int, input().split())
graph = [[float("inf")] * N for _ in range(N)]
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1][t-1] = graph[t-1][s-1] = w
dist = floyd_warshall(graph, directed=False)
dist = floyd_warshall(dist <= L, directed=False)
dist[dist == float("inf")] = 0.0

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(int(dist[s-1][t-1]) - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def io_tmp():
    global input
    import io, sys
    f = io.BytesIO(sys.stdin.buffer.read())
    input = f.readline

io_tmp()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = np.zeros((N, N), dtype=np.int64)
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1, t-1] = graph[t-1, s-1] = w
dist = floyd_warshall(graph, directed=False)
dist = floyd_warshall(dist <= L, directed=False)
dist[np.isinf(dist)] = 0.0

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(int(dist[s-1][t-1]) - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
from scipy.sparse import*
i=lambda:map(int,input().split())
f=csgraph.floyd_warshall
I=9e9
n,m,l=i()
d=eval('[I]*-~n,'*-~n)
exec('a,b,c=i();d[a][b]=c;'*m)
d=f(d,0)
d[d>l]=I
d[d<I]=1
d=f(d)
d[d>I]=I
q,=i()
while q:s,t=i();print(int(d[s,t]%I)-1);q-=1

Submission status: Accepted

Solution code:
def io_tmp():
    global input
    import io
    f = io.StringIO(open(0).read())
    input = f.readline

io_tmp()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = np.zeros((N, N), dtype=np.int64)
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1, t-1] = graph[t-1, s-1] = w
dist = floyd_warshall(graph, directed=False)
dist = floyd_warshall(dist <= L, directed=False)
dist[np.isinf(dist)] = 0.0

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(int(dist[s-1][t-1]) - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def io_tmp():
    global input
    import io, sys
    #f = io.StringIO(open(0).read())
    f = io.BytesIO(sys.stdin.buffer.read())
    input = f.readline

io_tmp()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = [[float("inf")] * N for _ in range(N)]
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1][t-1] = graph[t-1][s-1] = w
dist = floyd_warshall(graph, directed=False)
graph = dist <= L
#np.fill_diagonal(graph, 0)
#graph[dist > L] = 0
dist = floyd_warshall(graph, directed=False)
dist[np.isinf(dist)] = 0
#dist = dist.astype(int)

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(int(dist[s-1][t-1]) - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def io_tmp():
    global input
    import io, sys
    #f = io.StringIO(open(0).read())
    f = io.BytesIO(sys.stdin.buffer.read())
    input = f.readline

io_tmp()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = [[float("inf")] * N for _ in range(N)]
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1][t-1] = graph[t-1][s-1] = w
dist = floyd_warshall(graph, directed=False)
graph = dist <= L
#np.fill_diagonal(graph, 0)
#graph[dist > L] = 0
dist = floyd_warshall(graph, directed=False)
dist[np.isinf(dist)] = 0
dist = dist.astype(int)

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(dist[s-1][t-1] - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
from scipy.sparse import*
f=csgraph.floyd_warshall
I=9e9
i=lambda:map(int,input().split())
n,m,l=i()
d=eval('[I]*-~n,'*-~n)
while m:a,b,c=i();d[a][b]=c;m-=1
d=f(d,0)
d[d>l]=I
d[d<I]=1
d=f(d)
q,=i()
d[d>I]=I
while q:s,t=i();print(int(d[s,t]%I)-1);q-=1

Submission status: Accepted

Solution code:
def io_tmp():
    global input
    import io, sys
    #f = io.StringIO(open(0).read())
    f = io.BytesIO(sys.stdin.buffer.read())
    input = f.readline

io_tmp()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = [[0] * N for _ in range(N)]
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1][t-1] = graph[t-1][s-1] = w
dist = floyd_warshall(graph, directed=False)
graph = dist <= L
#np.fill_diagonal(graph, 0)
#graph[dist > L] = 0
dist = floyd_warshall(graph, directed=False)
dist[np.isinf(dist)] = 0
dist = dist.astype(int)

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(dist[s-1][t-1] - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def io_tmp():
    global input
    import io
    f = io.StringIO(open(0).read())
    input = f.readline

io_tmp()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = [[0] * N for _ in range(N)]
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1][t-1] = graph[t-1][s-1] = w
dist = floyd_warshall(graph, directed=False)
graph = dist <= L
#np.fill_diagonal(graph, 0)
#graph[dist > L] = 0
dist = floyd_warshall(graph, directed=False)
dist[dist == np.inf] = 0.0
dist = dist.astype(np.int)

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(dist[s-1][t-1] - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def io_tmp():
    global input
    import io
    f = io.StringIO(open(0).read())
    input = f.readline

io_tmp()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = [[0] * N for _ in range(N)]
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1][t-1] = graph[t-1][s-1] = w
dist = floyd_warshall(graph, directed=False)
graph = dist <= L
#np.fill_diagonal(graph, 0)
#graph[dist > L] = 0
dist = floyd_warshall(graph, directed=False)
dist[np.isinf(dist)] = 0
dist = dist.astype(int)

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(dist[s-1][t-1] - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
from scipy.sparse import*
f=csgraph.floyd_warshall
I=9e9
n,m,l,*t=map(int,open(0).read().split())
d=eval('[I]*-~n,'*-~n)
for a,b,c in zip(*[iter(t[:m*3])]*3):d[a][b]=c
d=f(d,0)
d[d>l]=I
d[d<I]=1
d=f(d)
for i in zip(*[iter(t[m*3+1:])]*2):print((I>d[i])*int(d[i])-1)

Submission status: Accepted

Solution code:
def io_tmp():
    global input
    import io
    f = io.StringIO(open(0).read())
    input = f.readline

io_tmp()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = np.zeros((N, N), dtype=np.int64)
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1, t-1] = graph[t-1, s-1] = w
dist = floyd_warshall(graph, directed=False)
graph = dist <= L
#np.fill_diagonal(graph, 0)
#graph[dist > L] = 0
dist = floyd_warshall(graph, directed=False)
dist[np.isinf(dist)] = 0
dist = dist.astype(int)

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(dist[s-1][t-1] - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def io_tmp():
    global input
    import io
    f = io.StringIO(open(0).read())
    input = f.readline

io_tmp()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = np.zeros((N, N), dtype=np.int64)
for _ in range(M):
    s, t, w = map(int, input().split())
    if w <= L:
        graph[s-1, t-1] = graph[t-1, s-1] = w
dist = floyd_warshall(graph, directed=False)
graph = np.ones((N, N))
np.fill_diagonal(graph, 0)
graph[dist > L] = 0
dist = floyd_warshall(graph, directed=False)
dist[np.isinf(dist)] = 0
dist = dist.astype(int)

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(dist[s-1][t-1] - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def io_tmp():
    global input
    import io
    f = io.StringIO(open(0).read())
    input = f.readline

io_tmp()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = np.zeros((N, N), dtype=np.int64)
for _ in range(M):
    s, t, w = map(int, input().split())
    graph[s-1, t-1] = graph[t-1, s-1] = w
dist = floyd_warshall(graph, directed=False)
graph = np.ones((N, N))
np.fill_diagonal(graph, 0)
graph[dist > L] = np.inf
dist = floyd_warshall(graph, directed=False)
dist[np.isinf(dist)] = 0
dist = dist.astype(int)

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(dist[s-1][t-1] - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def io_tmp():
    global input
    import io
    f = io.StringIO(open(0).read())
    input = f.readline

io_tmp()


from scipy.sparse.csgraph import floyd_warshall
import numpy as np

N, M, L = map(int, input().split())
graph = np.zeros((N, N), dtype=np.int64)
for _ in range(M):
    s, t, w = map(int, input().split())
    graph[s-1, t-1] = graph[t-1, s-1] = w
dist = floyd_warshall(graph, directed=False)
graph = np.ones((N, N), dtype=np.int64)
np.fill_diagonal(graph, 0)
graph[dist > L] = 0
dist = floyd_warshall(graph, directed=False)
dist[np.isinf(dist)] = 0
dist = dist.astype(int)

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    ans.append(dist[s-1][t-1] - 1)
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def io_tmp():
    global input
    import io
    f = io.StringIO(open(0).read())
    input = f.readline

io_tmp()


from scipy.sparse.csgraph import floyd_warshall


N, M, L = map(int, input().split())
graph = [[0] * N for _ in range(N)]
for _ in range(M):
    s, t, w = map(int, input().split())
    graph[s-1][t-1] = graph[t-1][s-1] = w
dist = floyd_warshall(graph, directed=False)
graph = [[0] * N for _ in range(N)]
for i in range(N):
    for j in range(i+1, N):
        if dist[i][j] <= L:
            graph[i][j] = graph[i][j] = 1
dist = floyd_warshall(graph, directed=False)

Q = int(input())
ans = []
for _ in range(Q):
    s, t = map(int, input().split())
    d = dist[s-1][t-1]
    if d == float("inf"):
        ans.append(-1)
    else:
        ans.append(int(d - 1))
print(*ans, sep='\n')

Submission status: Accepted

Solution code:
def io_tmp():
    global input
    import io, sys
    f = io.StringIO(open(0).read())
    input = f.readline

io_tmp()


from scipy.sparse.csgraph import floyd_warshall


N, M, L = map(int, input().split())
graph = [[0] * N for _ in range(N)]
for _ in range(M):
    s, t, w = map(int, input().split())
    graph[s-1][t-1] = graph[t-1][s-1] = w
dist = floyd_warshall(graph, directed=False)
graph = [[0] * N for _ in range(N)]
for i in range(N):
    for j in range(i+1, N):
        if dist[i][j] <= L:
            graph[i][j] = graph[i][j] = 1
dist = floyd_warshall(graph, directed=False)

Q = int(input())
for _ in range(Q):
    s, t = map(int, input().split())
    ans = dist[s-1][t-1]
    if ans == float("inf"):
        print(-1)
    else:
        print(int(ans - 1))

Submission status: Accepted

Solution code:
# ABC143E - Travel by Car
def floyd_warshall(dist):
    """
    Compute the shortest paths of all pairs and modify dist.
    """
    V = len(dist)
    for i in range(V):  # intermediate point
        for j, c2 in enumerate(dist[j][i] for j in range(V)):  #  source
            for k, (c1, c3) in enumerate(zip(dist[j], dist[i])):  # target
                if c2 + c3 < c1:
                    dist[j][k] = c2 + c3


def main():
    # FW -> once more FW to edges <= L
    N, M, L, *X = map(int, open(0).read().split())
    ABC, ST = X[: 3 * M], X[3 * M + 1 :]
    INF = float("inf")
    dist = [[INF] * (N + 1) for _ in range(N + 1)]
    for i in range(N + 1):
        dist[i][i] = 0
    for v, u, cost in zip(*[iter(ABC)] * 3):
        dist[v][u] = dist[u][v] = cost
    floyd_warshall(dist)

    # assume distance within L as 1 and compute the number of fueling
    modified_dist = [[1 if x <= L else INF for x in d] for d in dist]
    floyd_warshall(modified_dist)
    ans = [
        modified_dist[s][t] - 1 if modified_dist[s][t] != INF else -1
        for s, t in zip(*[iter(ST)] * 2)
    ]
    print("\n".join(map(str, ans)))


if __name__ == "__main__":
    main()

Submission status: Accepted

Solution code:
# ABC143E - Travel by Car
def floyd_warshall(dist):
    """
    Compute the shortest paths of all pairs and modify dist.
    """
    for i in range(N + 1):  # intermediate point
        for j, c2 in enumerate(dist[j][i] for j in range(N + 1)):  #  source
            for k, (c1, c3) in enumerate(zip(dist[j], dist[i])):  # target
                if c2 + c3 < c1:
                    dist[j][k] = c2 + c3
    return dist

def main():
    # FW -> once more FW to edges <= L
    global N
    N, M, L, *X = map(int, open(0).read().split())
    ABC, ST = X[: 3 * M], X[3 * M + 1 :]
    INF = float("inf")
    dist = [[INF] * (N + 1) for _ in range(N + 1)]
    for i in range(N + 1):
        dist[i][i] = 0
    for v, u, cost in zip(*[iter(ABC)] * 3):
        dist[v][u] = dist[u][v] = cost
    dist = floyd_warshall(dist)

    # assume distance within L as 1 and compute the number of fueling
    modified_dist = [[1 if x <= L else INF for x in d] for d in dist]
    modified_dist = floyd_warshall(modified_dist)
    ans = [
        modified_dist[s][t] - 1 if modified_dist[s][t] != INF else -1
        for s, t in zip(*[iter(ST)] * 2)
    ]
    print("\n".join(map(str, ans)))


if __name__ == "__main__":
    main()

Submission status: Accepted

Solution code:
def main():
	from scipy.sparse.csgraph import floyd_warshall
	import numpy as np
	n, m, l, *L = map(int, open(0).read().split())
	abc = L[:3 * m];
	st = L[3 * m + 1:]
	r = [[float("inf")] * n for _ in range(n)]
	for a, b, c in zip(*[iter(abc)] * 3):
		if c <= l: r[a - 1][b - 1] = c
	fw = floyd_warshall(r, 0)
	ans = floyd_warshall(np.where(fw <= l, 1, fw), 0) - 1
	for s, t in zip(*[iter(st)] * 2):
		x = ans[s - 1, t - 1]
		if x == float("inf"):
			print(-1)
		else:
			print(int(x))


if __name__ == "__main__":
	main()

#after contest

Submission status: Accepted

Solution code:
import sys
sys.setrecursionlimit(2147483647)
INF=float("inf")
MOD=10**9+7
input=lambda :sys.stdin.readline().rstrip()
from scipy.sparse.csgraph import floyd_warshall
n,m,L=map(int,input().split())
A=[[INF]*n for _ in range(n)]
for _ in range(m):
    a,b,c=map(int,input().split())
    a-=1; b-=1
    A[a][b]=A[b][a]=c
A=floyd_warshall(A)
B=[[INF]*n for _ in range(n)]
for i in range(n):
    for j in range(n):
        if(A[i][j]<=L): B[i][j]=1
B=floyd_warshall(B)
Q=int(input())
for _ in range(Q):
    s,t=map(int,input().split())
    s-=1; t-=1
    print(int(B[s][t])-1 if(B[s][t]!=INF) else -1)

Submission status: Accepted

Solution code:
from scipy.sparse.csgraph import floyd_warshall


N, M, L = map(int, input().split())
graph = [[0] * N for _ in range(N)]
for _ in range(M):
    s, t, w = map(int, input().split())
    graph[s-1][t-1] = graph[t-1][s-1] = w
dist = floyd_warshall(graph, directed=False)
graph = [[0] * N for _ in range(N)]
for i in range(N):
    for j in range(i+1, N):
        if dist[i][j] <= L:
            graph[i][j] = graph[i][j] = 1
dist = floyd_warshall(graph, directed=False)

Q = int(input())
for _ in range(Q):
    s, t = map(int, input().split())
    ans = dist[s-1][t-1]
    if ans == float("inf"):
        print(-1)
    else:
        print(int(ans - 1))