Graph Algorithms Reference Sheet
breadth-first-search() {
make a queue of nodes.
enqueue the start node.
color the start node yellow.
while (the queue is not empty) {
dequeue a node from the queue.
color that node green.
for (each neighboring node) {
if (that node is gray) {
color the node yellow.
enqueue it.
}
}
}
}
dijkstra's-algorithm() {
make a priority queue of nodes.
enqueue the start node at distance 0.
color the start node yellow.
while (the queue is not empty) {
dequeue a node from the queue.
if (that node isn't green) {
color that node green.
for (each neighboring node) {
if (that node is not green) {
color the node yellow.
enqueue it at the new distance.
}
}
}
}
}
aStarSearch() {
make a priority queue of nodes.
enqueue the start node at distance 0.
color the start node yellow.
while (the queue is not empty) {
dequeue a node from the queue.
if (that node isn't green) {
color that node green.
for (each neighboring node) {
if (that node is not green) {
color the node yellow.
enqueue it at the new distance plus the heuristic.
}
}
}
}
}
kruskals-algorithm() {
remove all edges from the graph.
put each node into its own cluster.
for (each edge, in increasing order of cost) {
if (the edge’s endpoints are in different clusters) {
add that edge back to the graph.
merge those two clusters.
}
}
return the edges added back.
}