Section 27.3 Check Point Questions3 questions

27.3.1

What is the output of the following code?

vector<WeightedEdge> v;
v.push_back(WeightedEdge(1, 2, 3.5)); 
v.push_back(WeightedEdge(1, 6, 6.5)); 
v.push_back(WeightedEdge(1, 7, 1.5)); 
cout << v[0].weight << endl;
cout << v[1].weight << endl;
cout << v[2].weight << endl;

27.3.2

What is the output of the following code?

priority_queue<WeightedEdge, vector<WeightedEdge>, 
  greater<WeightedEdge>> q;
q.push(WeightedEdge(1, 2, 3.5)); 
q.push(WeightedEdge(1, 6, 6.5)); 
q.push(WeightedEdge(1, 7, 1.5)); 
cout << q.top().weight << endl;
q.pop();
cout << q.top().weight << endl;
q.pop();
cout << q.top().weight << endl;

27.3.3

What is wrong in the following code? Fix it and show the output.

vector<vector<WeightedEdge>> neighbors;
neighbors[0].push_back(WeightedEdge(0, 2, 3.5)); 
neighbors[0].push_back(WeightedEdge(0, 6, 6.5)); 

neighbors[0].push_back(WeightedEdge(0, 7, 1.5)); 
neighbors[1].push_back(WeightedEdge(1, 0, 3.5)); 
neighbors[1].push_back(WeightedEdge(1, 5, 8.5)); 
neighbors[1].push_back(WeightedEdge(1, 8, 19.5)); 
cout << neighbors[0][0] << endl;