output_description: For each vertex, print its ID and the distance separated by a space character
  in a line respectively. Print in order of vertex IDs.
input_description: In the first line, an integer $n$ denoting the number of vertices in $G$ is
  given. In the following $n$ lines, adjacency lists for each vertex $u$ are
  respectively given in the following format:
  
  $u$ $k$ $v_1$ $c_1$ $v_2$ $c_2$ ... $v_k$ $c_k$
  
  Vertices in $G$ are named with IDs $0, 1, ..., n-1$. $u$ is ID of the target
  vertex and $k$ denotes its degree. $v_i (i = 1, 2, ... k)$ denote IDs of
  vertices adjacent to $u$ and $c_i$ denotes the weight of a directed edge
  connecting $u$ and $v_i$ (from $u$ to $v_i$).
attempt: n = int(input())
  G = [[] for i in range(n)]
  for ni in range(n):
      u, k, *tmp = [int(i) for i in input().split()]
      for ki in range(k):
          G[ni].append(tmp[:2])
          del tmp[:2]
  
  INF = 100 * 100000
  D = [INF for i in range(n)]
  D[0] = 0
  C = [0 for i in range(n)]
  while 0 in C:
      U = [INF if C[i] == 1 else D[i] for i in range(n)]
      u = U.index(min(U))
  
      for i in range(len(G[u])):
          v = G[u][i][0]
          if D[u] + G[u][i][1] < D[v]:
              D[v] = D[u] + G[u][i][1]
      C[u] = 1
  
  for ni in range(n):
      print(ni, D[ni])
  
problem_description: Single Source Shortest Path
  
  For a given weighted graph $G = (V, E)$, find the shortest path from a source
  to each vertex. For each vertex $u$, print the total weight of edges on the
  shortest path from vertex $0$ to $u$.
samples: [{"input": "5\n    0 3 2 3 3 1 1 2\n    1 2 0 2 3 4\n    2 3 0 3 3 1 4 1\n    3 4 2 1 0 1 1 4 4 3\n    4 2 2 1 3 3", "output": "0 0\n    1 2\n    2 2\n    3 1\n    4 3"}]