Solving the above problem by vertex cover approach results in exponential tim algorithm but this can be solved by maximizing flows using Ford Fulkerson algorithm Above problem can be solved using Ford Fulkerson.
- Create a path from source(0) to all nodes of the graph with capacity = t.
- Create a path from from all nodes to target(1) with capacity = 1.
- Find a max flow of the above modified graph using Ford Fulkerson.
Ford Fulkerson Algorithm to find max flow in the given Graph
- Find a path from source to target in the graph.
- Find the minimum flow along the path.
- Increase the flow of all edges along the path by min flow calculated above
- Store the min flow of the path.
Repeat the above 4 steps till no augmenting path possible.
Explanation for Ford Fulkerson Alogrithm
Chose one possible path and identify the edge with the smallest capacity. Record this number Substract this number from each number on that path. This is the new capacity for each arc long the path. Chose another route and repeat step 1 once again record the smallest capacity. Repeat untill all possible path are exhausted. Add the smallest capacities of all routes. This is the minimum carrying capacity of the network
Reference
http://anandtechblog.blogspot.in/search/label/Ford%20Fulkerson%20algorithm