public void GivenSingleStepPathsWhenFindShortestPathsThenReturnSimple()
{
// arrange
var start = new SimpleNode("START");
var a = new SimpleNode("A");
var b = new SimpleNode("B");
var c = new SimpleNode("C");
var arcs = new IArcWithLength <SimpleNode>[]
{
new SimpleArcWithLength <SimpleNode>(start, a, 1),
new SimpleArcWithLength <SimpleNode>(start, b, 2),
new SimpleArcWithLength <SimpleNode>(start, c, 3),
};
// act
var foundPaths = arcs.FindShortestPaths(start);
// assert
Assert.AreEqual(3, foundPaths.Count);
Assert.IsTrue(foundPaths.All(p => p.From == start && p.Path.Count == 1));
Assert.AreEqual(1, foundPaths.First(p => p.To == a).Lenght);
Assert.AreEqual(2, foundPaths.First(p => p.To == b).Lenght);
Assert.AreEqual(3, foundPaths.First(p => p.To == c).Lenght);
}
public void GivenCyclesWhenFindShortestPathsThenWorksFine()
{
// arrange
var start = new SimpleNode("START");
var a = new SimpleNode("A");
var b = new SimpleNode("B");
var c = new SimpleNode("C");
var arcs = new IArcWithLength <SimpleNode>[]
{
new SimpleArcWithLength <SimpleNode>(start, a, 1),
new SimpleArcWithLength <SimpleNode>(start, b, 10),
new SimpleArcWithLength <SimpleNode>(start, c, 10),
new SimpleArcWithLength <SimpleNode>(a, b, 1),
new SimpleArcWithLength <SimpleNode>(b, c, 1),
};
// act
var foundPaths = arcs.FindShortestPaths(start);
// assert
Assert.AreEqual(3, foundPaths.Count);
Assert.AreEqual(1, foundPaths.First(p => p.To == a).Lenght);
Assert.AreEqual(2, foundPaths.First(p => p.To == b).Lenght);
Assert.AreEqual(3, foundPaths.First(p => p.To == c).Lenght);
}
public SimplePathWithLenght(SimplePathWithLenght <NodeT> path, IArcWithLength <NodeT> arc)
: this(path.From, arc.To, new List <IArcWithLength <NodeT> >(path.Path) { arc }, path.Lenght + arc.Lenght)
{
if (path.To != arc.From)
{
throw new InvalidOperationException("To path node has to be the same as arcs From.");
}
}
public void GivenNegaativeLenghtArcWhenTryToFindShortestPathsThenThrowError()
{
// arrange
var start = new SimpleNode("START");
var a = new SimpleNode("A");
var arcs = new IArcWithLength <SimpleNode>[]
{
new SimpleArcWithLength <SimpleNode>(start, a, -1),
};
// act & assert
Assert.Throws <InvalidOperationException>(() => arcs.FindShortestPaths(start));
}
public void GivenNoArcsFromStartWhenFindShortestPathsThenReturnEmpty()
{
// arrange
var start = new SimpleNode("START");
var a = new SimpleNode("A");
var b = new SimpleNode("B");
var arcs = new IArcWithLength <SimpleNode>[]
{
new SimpleArcWithLength <SimpleNode>(a, b, 10),
};
// act
var foundPaths = arcs.FindShortestPaths(start);
// assert
Assert.AreEqual(0, foundPaths.Count);
}
