> #include <cstdio>
> #include <algorithm>
> using namespace std;
> 
> #define nocol -1
> #define mulcol -2
> 
> int n, p[10000][2], cn[20000];
> bool v[10001];
> int Len;
> 
> struct segment
> {
>        int l, r, col;
>        segment *lchild, *rchild;
>        void construct (int , int);
>        void insert (int ,int , int);
>        int find ();
> }*root, tree[320010];
> 
> void segment :: construct (int left, int right)
> {
>      if (left == right) {l = left; r= right; lchild = rchild = NULL; return;}
>      l = left; r = right;
>      lchild = &tree[Len ++]; rchild = &tree[Len ++];
>      if (left + 1 < right)
>      {
>               lchild->construct (left, (left + right)/2);
>               rchild->construct ((left + right)/2 + 1, right);
>      }
>      else
>      {
>          lchild->construct (left, left);
>          rchild->construct (right, right);
>      }
> }
> 
> void segment :: insert (int left, int right, int k)
> {
>      if (left <= cn[l] && cn[r] <= right)
>      {
>            col = k;
>      }
>      else
>      {
>          if (col != k) col = mulcol;
>          int mid = (l + r) / 2;
>          if (left <= cn[mid] && lchild) lchild->insert (left, right, k);
>          if (right >= cn[mid + 1] && rchild) rchild->insert (left, right, k);
>      }
> }
> 
> int segment :: find ()
> {
>     int tmp1, tmp2;
>     if (col >= 0 && !v[col]) {v[col] = true; return 1;}
>     
>     if (col == nocol || v[col]) return 0;
>     else if (col == mulcol)
>     {
>          tmp1 = tmp2 = 0;
>          if (lchild) tmp1 += lchild->find ();
>          if (rchild) tmp2 += rchild->find ();
>          return tmp1 + tmp2;
>     }
> }
> 
> void solve ()
> {
>     int i, j, k, num;
>     scanf ("%d", &n);
>     for (i = 0, j = 0; i < n; i ++)
>     {
>         scanf ("%d %d", &p[i][0], &p[i][1]);
>         cn[j ++] = p[i][0]; cn[j ++] = p[i][1];
>     }
>     num = j;
>     sort(cn, cn + num);
>     int tmp;
你下面这里的程序是O(n^2)的，很慢，在这超时了，另外你的程序结果也不对
>     for (i = 0; i < num; i ++)
>     {
>         for (j = i + 1; j < num; j ++)
>         if (cn[i] != cn[j]) break;
>         tmp = j - i - 1;
>         for (; j < num; j ++)
>         cn[j - tmp] = cn[j];
>         num -= tmp;
>     }
>     Len = 0;
>     root = &tree[Len ++];
>     root->construct(0, num - 1);
>     root->col = -1;
>     for (i = 0; i < n; i ++)
>     {
>         root->insert (p[i][0], p[i][1], i);
>     }
>     memset (v, false, sizeof (v));
>     
>     int sum = root->find ();
>     printf ("%d\n", sum);
> }
> 
> int main ()
> {
>     int c;
>     scanf ("%d", &c);
>     while (c --)
>     solve ();
>     return 0;
> }