/*
* For the unweighted graph, <name>:
*
* 1. The number of nodes is <name>Nodes.
* 2. The number of edges is <name>Edges.
* 3. An edge exists between <name>From[i] to <name>To[i].
*
*/
static int findShortest(int graphNodes, int[] graphFrom, int[] graphTo, long[] ids, long val)
{
List <int> maxInts = new List <int>();
int minDist = int.MaxValue;
GraphAPI gapi = new GraphAPI(graphNodes, ids);
for (int i = 0; i < graphFrom.Length; i++)
{
gapi.AddEdge(graphFrom[i], graphTo[i]);
}
List <int> impNodes = new List <int>();
for (int i = 0; i < graphNodes; i++)
{
if (ids[i] == val)
{
impNodes.Add(i);
}
}
for (int i = 0; i < impNodes.Count; i++)
{
BreadthFirstSearch bfs = new BreadthFirstSearch(gapi, gapi.S, impNodes[i], val);
minDist = Math.Min(minDist, bfs.minDist);
//List<int> innerValues = new List<int>();
//for (int j = 0; j < graphNodes; j++)
//{
// if (ids[j] == val)
// {
// innerValues.Add(dfs.DistTo[j]);
// }
//}
//innerValues.Sort();
//if (innerValues.Count > 1)
//{
// maxInts.Add(innerValues[0] + innerValues[1]);
//}
}
//maxInts.Sort();
return(minDist != int.MaxValue ? minDist : -1);
}
static long roadsAndLibraries(int n, long c_lib, long c_road, int[][] cities)
{
GraphAPI gapi = new GraphAPI(n);
for (int i = 0; i < cities.Length; i++)
{
gapi.AddEdge(cities[i][0], cities[i][1]);
}
ConnectedComponents bfs = new ConnectedComponents(gapi, n);
long result = ((c_road * bfs.RoadCount()) + (bfs.LibraryCount() * c_lib));
if (c_lib * n < result)
{
result = c_lib * n;
}
return(result);
}
/*Suppose that we have n groups, of sizes a1 to an. Except when n is smallish, the following formula for the number N of ways
* to choose a pair of people from different groups is more efficient:
* N=((a1+⋯+an)^2 − (a1^2 +⋯+ an^2)) / 2.
* To see that the formula does the job, expand (a1+⋯+an)2.*/
static long journeyToMoon(int n, int[][] astronaut)
{
GraphAPI gapi = new GraphAPI(n);
for (int i = 0; i < astronaut.Length; i++)
{
gapi.AddEdge(astronaut[i][0], astronaut[i][1]);
}
ConnectedComponents bfs = new ConnectedComponents(gapi, n);
IList <long> IdCount = new List <long>();
IdCount.Add(1);
Array.Sort(bfs.Id);
for (int k = 0; k < n - 1; k++)
{
if (bfs.Id[k] == bfs.Id[k + 1])
{
++IdCount[IdCount.Count - 1];
continue;
}
IdCount.Add(1);
}
long SumSquare = 0;
for (int i = 0; i < IdCount.Count; i++)
{
SumSquare += IdCount[i];
}
SumSquare = (long)Math.Pow(SumSquare, 2);
long SquareSum = 0;
for (int i = 0; i < IdCount.Count; i++)
{
SquareSum += (long)Math.Pow(IdCount[i], 2);
}
return((SumSquare - SquareSum) / 2);
}
static int maxRegion(int[][] grid, int nodeCount)
{
GraphAPI gapi = new GraphAPI(nodeCount);
Dictionary <string, int> dict = new Dictionary <string, int>();
int nodeNumber = 1;
for (int i = 0; i < grid.Length; i++)
{
for (int j = 0; j < grid[i].Length; j++)
{
string key = i + "|" + j;
dict.Add(key, nodeNumber);
nodeNumber++;
}
}
for (int i = 0; i < grid.Length; i++)
{
for (int j = 0; j < grid[i].Length; j++)
{
if (grid[i][j] == 1)
{
var keyOuter = i + "|" + j;
var from = dict[keyOuter];
if (j > 0 && i < grid.Length - 1 && grid[i + 1][j - 1] == 1)
{
var keyInner = (i + 1) + "|" + (j - 1);
var to = dict[keyInner];
gapi.AddEdge(from, to);
}
if (j < grid[i].Length - 1 && grid[i][j + 1] == 1)
{
var keyInner = (i) + "|" + (j + 1);
var to = dict[keyInner];
gapi.AddEdge(from, to);
}
if (i < grid.Length - 1 && grid[i + 1][j] == 1)
{
var keyInner = (i + 1) + "|" + j;
var to = dict[keyInner];
gapi.AddEdge(from, to);
}
if (i < grid.Length - 1 && j < grid[i].Length - 1 && grid[i + 1][j + 1] == 1)
{
var keyInner = (i + 1) + "|" + (j + 1);
var to = dict[keyInner];
gapi.AddEdge(from, to);
}
}
}
}
CCForDFSHard cc = new CCForDFSHard(gapi);
Array.Sort(cc.Id);
return(cc.Id[cc.Id.Length - 1]);
}
