public void Solve()
{
Init();
Queue <List <int> > cand = new Queue <List <int> >(), nextCand;
Queue <int> range = new Queue <int>(), nextRange;
cand.Enqueue(Enu.Range(0, NQ).ToList());
range.Enqueue(0); range.Enqueue(M);
var ans = new int[NQ];
for (; cand.Count > 0; cand = nextCand, range = nextRange)
{
nextCand = new Queue <List <int> >();
nextRange = new Queue <int>();
var uf = new UnionFind(N);
while (cand.Count > 0)
{
var who = cand.Dequeue();
int L = range.Dequeue(), R = range.Dequeue(), mid = L + R >> 1;
for (int i = L; i < mid; i++)
{
uf.Unite(E[i][0], E[i][1]);
}
var next = new[] { new List <int>(), new List <int>() };
foreach (int i in who)
{
int num = uf.Count(Q[i][0]) + (uf.Same(Q[i][0], Q[i][1]) ? 0 : uf.Count(Q[i][1]));
if (num >= Q[i][2])
{
ans[i] = mid; next[0].Add(i);
}
else
{
next[1].Add(i);
}
}
for (int i = mid; i < R; i++)
{
uf.Unite(E[i][0], E[i][1]);
}
if (L == R - 1)
{
who.ForEach(i => ans[i] = R); continue;
}
nextCand.Enqueue(next[0]); nextCand.Enqueue(next[1]);
nextRange.Enqueue(L); nextRange.Enqueue(mid);
nextRange.Enqueue(mid); nextRange.Enqueue(R);
}
}
Console.WriteLine(string.Join("\n", ans));
}
public int RegionsBySlashes(string[] grid)
{
var N = grid.Length;
var uf = new UnionFind(4 * N * N);
for (int i = 0; i < N; i++)
{
for (int j = 0; j < N; j++)
{
if (i > 0)
{
uf.Union(ComputeIndex(i, j, 0, N), ComputeIndex(i - 1, j, 2, N));
}
if (j > 0)
{
uf.Union(ComputeIndex(i, j, 3, N), ComputeIndex(i, j - 1, 1, N));
}
if (grid[i][j] != '\\')
{
uf.Union(ComputeIndex(i, j, 0, N), ComputeIndex(i, j, 3, N));
uf.Union(ComputeIndex(i, j, 1, N), ComputeIndex(i, j, 2, N));
}
if (grid[i][j] != '/')
{
uf.Union(ComputeIndex(i, j, 0, N), ComputeIndex(i, j, 1, N));
uf.Union(ComputeIndex(i, j, 2, N), ComputeIndex(i, j, 3, N));
}
}
}
return(uf.Count());
}
//实现1.5.2.1
static void Main()
{
int totalIDs = 50000000;
int unions = 200000;
int offset = unions / 2;
UnionFind uf = new UnionFind(totalIDs);
UnionFind uf_quick = new UnionFind(totalIDs); //使用快速连接
UnionFind uf_quick_compress = new UnionFind(totalIDs); //使用路径压缩和快速连接
//uf.Union(0, 1);
//uf.Union(0, 5);
//uf.Union(2, 6);
//uf.Union(6, 7);
//uf.Union(3, 8);
//uf.Union(3,9);
//uf.Union(4, 3);
//uf.Union_UnionSubTree(0, 1);
//uf.Union_UnionSubTree(0, 5);
//uf.Union_UnionSubTree(2, 6);
//uf.Union_UnionSubTree(6, 7);
//uf.Union_UnionSubTree(3, 8);
//uf.Union_UnionSubTree(3, 9);
//uf.Union_UnionSubTree(4, 3);
int[] links = Common.GenerateRadomData(unions, 0, totalIDs);
Stopwatch Stopwatch1 = new Stopwatch();
Stopwatch1.Start();
for (int i = 0; i < offset; ++i)
{
;//uf.Union(links[i], links[i + offset]);
}
Stopwatch1.Stop();
Console.WriteLine("没有优化Use :" + Stopwatch1.ElapsedMilliseconds.ToString());
Console.WriteLine(uf.Count());
//quick-union
Stopwatch Stopwatch2 = new Stopwatch();
Stopwatch2.Start();
for (int i = 0; i < offset; ++i)
{
uf_quick.Union_QuickUnion(links[i], links[i + offset]);
}
Stopwatch2.Stop();
Console.WriteLine("快速union Use :" + Stopwatch2.ElapsedMilliseconds.ToString());
Console.WriteLine(uf_quick.Count());
//quick-union和压缩路径
Stopwatch Stopwatch3 = new Stopwatch();
Stopwatch3.Start();
for (int i = 0; i < offset; ++i)
{
uf_quick_compress.Union_UnionSubTree(links[i], links[i + offset]);
}
Stopwatch3.Stop();
Console.WriteLine("快速union+路径压缩 use :" + Stopwatch3.ElapsedMilliseconds.ToString());
Console.WriteLine(uf_quick_compress.Count());
Console.ReadKey();
}
public bool ValidTree(int n, int[,] edges)
{
UnionFind uf = new UnionFind(n);
for (int i = 0; i < edges.GetLength(0); i++)
{
// 已经在一个集合中，形成了环
if (!uf.Union(edges[i, 0], edges[i, 1]))
{
return(false);
}
}
// 只有一个集合才是树
return(uf.Count() == 1);
}
public int FindCircleNum(int[][] M)
{
int n = M.length;
UnionFind uf = new UnionFind(n);
for (int i = 0; i < n - 1; i++)
{
for (int j = i + 1; j < n; j++)
{
if (M[i][j] == 1)
{
uf.Union(i, j);
}
}
}
return(uf.Count());
}
public int ClosedIsland(int[][] grid)
{
var N = grid.Length;
var M = grid[0].Length;
var uf = new UnionFind(grid);
for (int i = 0; i < N; i++)
{
for (int j = 0; j < M; j++)
{
if (grid[i][j] == 0)
{
if (i == 0 || j == 0 || i == N - 1 || j == M - 1)
{
uf.Union(i * M + j, N * M);
}
if (i - 1 >= 0 && grid[i - 1][j] == 0)
{
uf.Union(i * M + j, (i - 1) * M + j);
}
if (i + 1 < N && grid[i + 1][j] == 0)
{
uf.Union(i * M + j, (i + 1) * M + j);
}
if (j - 1 >= 0 && grid[i][j - 1] == 0)
{
uf.Union(i * M + j, i * M + j - 1);
}
if (j + 1 < M && grid[i][j + 1] == 0)
{
uf.Union(i * M + j, i * M + j + 1);
}
}
}
}
return(uf.Count() - 1);
}
public int FindCircleNum(int[,] M)
{
if (M == null || M.GetLength(0) == 0 || M.GetLength(1) == 0)
{
return(0);
}
int n = M.GetLength(0);
UnionFind uf = new UnionFind(n);
for (int i = 0; i < n; i++)
{
for (int j = i + 1; j < n; j++)
{
if (M[i, j] == 1)
{
uf.Union(i, j);
}
}
}
return(uf.Count());
}
public int NumIslands(char[][] grid)
{
if (grid == null || grid.Length == 0 || grid[0].Length == 0)
{
return(0);
}
var uf = new UnionFind(grid);
int m = grid.Length;
int n = grid[0].Length;
for (int i = 0; i < m; i++)
{
for (int j = 0; j < n; j++)
{
if (grid[i][j] == '1')
{
if (i - 1 >= 0 && grid[i - 1][j] == '1')
{
uf.Union(i * n + j, (i - 1) * n + j);
}
if (i + 1 < m && grid[i + 1][j] == '1')
{
uf.Union(i * n + j, (i + 1) * n + j);
}
if (j - 1 >= 0 && grid[i][j - 1] == '1')
{
uf.Union(i * n + j, i * n + j - 1);
}
if (j + 1 < n && grid[i][j + 1] == '1')
{
uf.Union(i * n + j, i * n + j + 1);
}
}
}
}
return(uf.Count());
}
static void Main()
{
var nm = ReadInts();
int n = nm[0], m = nm[1];
var edges = new List <Edge>();
for (int i = 0; i < m; i++)
{
var aby = ReadInts();
edges.Add(new Edge {
a = aby[0] - 1, b = aby[1] - 1, y = aby[2]
});
}
int q = ReadInt();
var qs = new List <Query>();
for (int i = 0; i < q; i++)
{
var vw = ReadInts();
qs.Add(new Query {
v = vw[0] - 1, w = vw[1], index = i
});
}
var uf = new UnionFind(n);
edges.Sort((a, b) => - a.y.CompareTo(b.y));
qs.Sort((a, b) => - a.w.CompareTo(b.w));
int p = 0;
var ans = new int[qs.Count];
for (int i = 0; i < qs.Count; i++)
{
int v = qs[i].v; // ??
int w = qs[i].w; // w ???????????????
while (p < edges.Count && edges[p].y > w)
{
uf.Unite(edges[p].a, edges[p].b);
p++;
}
ans[qs[i].index] = uf.Count(v);
}
var sb = new StringBuilder();
foreach (var a in ans)
{
sb.AppendLine(a.ToString());
}
Console.Write(sb.ToString());
/*
* Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
* for (int i = 0; i < ans.Length; i++) {
* Console.WriteLine(ans[i]);
* }
* Console.Out.Flush();
*/
}
public int NumIslands(char[][] grid)
{
//verification
if (grid == null || grid.Length == 0)
{
return(0);
}
rows = grid.Length;
cols = grid[0].Length;
int count = 0;
//M1:DFS. O(mn), O(mn)
// for(int i=0; i<rows; i++){
// for(int j=0; j<cols; j++){
// if(grid[i][j]=='1'){
// count++;
// DFS(grid, i,j);
// }
// }
// }
//BFS. O(mn), O(mn)
// Queue<int[]> queue=new Queue<int[]>();
// for(int i=0; i<rows; i++){
// for(int j=0; j<cols; j++){
// if(grid[i][j]=='1'){
// count++;
// queue.Enqueue(new int[]{i,j});
// while(queue.Any()){
// var p=queue.Dequeue();
// for(int k=0; k<4; k++){
// var newx=p[0]+directions[k,0];
// var newy=p[1]+directions[k,1];
// if(IsLand(grid, newx, newy)){
// grid[newx][newy]='0';
// queue.Enqueue(new int[]{newx, newy});
// }
// }
// }
// }
// }
// }
// return count;
//M3: Disjoint set
int[,] dir = { { 1, 0 }, { 0, 1 } };
int node = rows * cols;
UnionFind uf = new UnionFind(node + 1);
for (int i = 0; i < rows; i++)
{
for (int j = 0; j < cols; j++)
{
if (grid[i][j] == '0')
{
uf.Union(GetIndex(i, j), node);
}
else if (grid[i][j] == '1')
{
for (int d = 0; d < 2; d++)
{
var x = i + dir[d, 0];
var y = j + dir[d, 1];
if (x < rows && y < cols && grid[x][y] == '1')
{
uf.Union(GetIndex(i, j), GetIndex(x, y));
}
}
}
}
}
return(uf.Count() - 1);
}
