weighted graph

general
,
1

how to construct a weighted graph in c++ using stl’s

2

1> if you want to store just edges make

vector< pair< int, pair < int,int> > > edges.

pair of int(weight) and pair(a,b)(edge from atob).

or you can make pair of pair(a,b)(edge from atob) and int(weight).

2> if you want to store edges from perticular nodes.

vector< pair< int,int> > nodes[N];

for edges a to b with weight w you can insert as nodes[a].push_back(make _ pair(b,w))
indicating a has edge to b with weight w.

this 2 are just simple examples there are many ways to do so. :slight_smile:

If you do not know how vector and pair works use below links.

Link for PAIR || Link for Vector

EDIT: This approach will help you specially when you need to sort the edges according to weight.
you can use directly sort algorithm on vector as everything is mapped.

3

you can simply use:
N->no of nodes in the graph

vector<int> edges[N];//storing edges
vector<int> cost[N];//storing wieght

If you want to know the cost from a to b, in edges[a] search for b and using the index obtained extract the value from cost[a].