Find maximum weight cycle in an undirected graph in typescript
Ts program for Find maximum weight cycle in an undirected graph. Here more information.
/*
TypeScript program for
Maximum weight cycle in an undirected graph
*/
class AjlistNode
{
// Vertices node key
public id: number;
public weight: number;
public next: AjlistNode;
constructor(id: number, weight: number)
{
// Set value of node key
this.id = id;
this.weight = weight;
this.next = null;
}
}
class Vertices
{
public data: number;
public next: AjlistNode;
public last: AjlistNode;
constructor(data: number)
{
this.data = data;
this.next = null;
this.last = null;
}
}
class Graph
{
// Number of Vertices
public size: number;
public result: number;
public node: Vertices[];
constructor(size: number)
{
// Set value
this.size = size;
this.result = 0;
this.node = Array(size).fill(null);
this.setData();
}
// Set initial node value
public setData()
{
if (this.size <= 0)
{
console.log("\nEmpty Graph");
}
else
{
for (var index = 0; index < this.size; index++)
{
// Set initial node value
this.node[index] = new Vertices(index);
}
}
}
public connection(start: number, last: number, weight: number)
{
// Safe connection
var edge = new AjlistNode(last, weight);
if (this.node[start].next == null)
{
this.node[start].next = edge;
}
else
{
// Add edge at the end
this.node[start].last.next = edge;
}
// Get last edge
this.node[start].last = edge;
}
// Handling the request of adding new edge
public addEdge(start: number, last: number, weight: number)
{
if (start >= 0 && start < this.size && last >= 0 && last < this.size)
{
this.connection(start, last, weight);
if (start == last)
{
return;
}
this.connection(last, start, weight);
}
else
{
// When invalid nodes
console.log("\nHere Something Wrong");
}
}
public printGraph()
{
if (this.size > 0)
{
// Print graph ajlist Node value
for (var index = 0; index < this.size; ++index)
{
console.log("\nAdjacency list of vertex " + index + " :");
var edge = this.node[index].next;
while (edge != null)
{
// Display graph node
console.log(" " + this.node[edge.id].data + "[" + edge.weight + "]");
// Visit to next edge
edge = edge.next;
}
}
}
}
public maximumCycle(start: number, last: number, visit: boolean[], sum: number)
{
if (start >= this.size || last >= this.size || start < 0 || last < 0 || this.size <= 0)
{
return;
}
if (visit[start] == true)
{
if (start == last && sum > this.result)
{
// When find a new max weight cycle
this.result = sum;
}
return;
}
// Here modified the value of visited node
visit[start] = true;
// This is used to iterate nodes edges
var edge = this.node[start].next;
while (edge != null)
{
this.maximumCycle(edge.id, last, visit, sum + (edge.weight));
// Visit to next edge
edge = edge.next;
}
// Reset the value of visited node status
visit[start] = false;
}
public maxWeightCycle()
{
if (this.size <= 0)
{
// Empty graph
return;
}
// Auxiliary space which is used to store
// information about visited node
var visit: boolean[] = Array(this.size).fill(false);
this.result = -Number.MAX_VALUE;
for (var i = 0; i < this.size; ++i)
{
// Check cycle of node i to i
// Here initial cycle weight is zero
this.maximumCycle(i, i, visit, 0);
}
if (this.result == -Number.MAX_VALUE)
{
console.log("\nMax weight cycle : None ");
}
else
{
console.log("\nMax weight cycle : " + this.result);
}
}
public static main(args: string[])
{
// 6 implies the number of nodes in graph
var g = new Graph(6);
// Connect node with an edge
// First and second parameter indicate node
// Last parameter is indicate weight
g.addEdge(0, 1, 3);
g.addEdge(0, 3, -3);
g.addEdge(0, 4, 7);
g.addEdge(0, 5, 1);
g.addEdge(1, 2, 11);
g.addEdge(1, 4, 8);
g.addEdge(1, 5, 0);
g.addEdge(2, 3, 1);
g.addEdge(2, 5, 5);
g.addEdge(3, 4, 2);
g.addEdge(4, 5, 8);
// Print graph element
g.printGraph();
// Test
g.maxWeightCycle();
}
}
Graph.main([]);
/*
file : code.ts
tsc --target es6 code.ts
node code.js
*/
Output
Adjacency list of vertex 0 :
1[3]
3[-3]
4[7]
5[1]
Adjacency list of vertex 1 :
0[3]
2[11]
4[8]
5[0]
Adjacency list of vertex 2 :
1[11]
3[1]
5[5]
Adjacency list of vertex 3 :
0[-3]
2[1]
4[2]
Adjacency list of vertex 4 :
0[7]
1[8]
3[2]
5[8]
Adjacency list of vertex 5 :
0[1]
1[0]
2[5]
4[8]
Max weight cycle : 34
Please share your knowledge to improve code and content standard. Also submit your doubts, and test case. We improve by your feedback. We will try to resolve your query as soon as possible.
New Comment