1 for(i = 0; i < n; ++i) {
 2             scanf("%d %d", &l, &r);
 3             if(vis[l] == 0){//如果没有访问过这个点..
 4                 vis[l] = 1;
 5                 s[tot++] = l;//就把这个点加到离散化的数组里..
 6             }
 7             if(vis[r] == 0) {
 8                 s[tot++] = r;
 9                 vis[r] = 1;
10             }
11             node[i].l = l, node[i].r = r;
12         }
13
14         sort(s, s+tot);
15
16         for(i = tot-1; i > 0; --i) {//在相邻的海报间增加一个点
17             if(s[i] - s[i-1] > 1)
18                 s[tot++] = s[i-1]+1;
19         }
20         sort(s, s+tot);
21
22         for(i = 0; i < n; ++i) {//s数组的下标就是离散化后的值..
23             l = solve(node[i].l, tot, s);
24             r = solve(node[i].r, tot, s);
25             modify(l, r, i, 0, tot, 1);
26         }
27
28
29 int solve(int key, int tot, int *arr)
30 {
31     int mid;
32     int l = 0, r = tot-1;
33     while(l <= r) {
34         mid = (l+r)>>1;
35         if(arr[mid] == key) return mid;
36         if(arr[mid] > key) r = mid-1;
37         else l = mid+1;
38     }
39 }

  1 #include <stdio.h>
  2 #include <cstring>
  3 #include <algorithm>
  4 using namespace std;
  5
  6 const int MAXN = 40010;
  7 int lazy[MAXN<<2];
  8 int arr[MAXN];
  9 int vis[10000010];
 10 int s[MAXN];
 11 int cnt;
 12
 13 struct Node
 14 {
 15     int r;
 16     int l;
 17 }node[MAXN];
 18
 19 void pushDown(int rt)
 20 {
 21     if(lazy[rt] != -1) {
 22         lazy[rt<<1] = lazy[rt<<1|1] = lazy[rt];
 23         lazy[rt] = -1;
 24     }
 25 }
 26
 27 void modify(int l, int r, int x, int L, int R, int rt)
 28 {
 29     if(l <= L && r >= R) {
 30         lazy[rt] = x;
 31         return;
 32     }
 33     pushDown(rt);
 34     int mid = (L+R) >> 1;
 35     if(l <= mid) modify(l, r, x, L, mid, rt<<1);
 36     if(mid < r) modify(l, r, x, mid+1, R, rt<<1|1);
 37 }
 38
 39 int solve(int key, int tot, int *arr)
 40 {
 41     int mid;
 42     int l = 0, r = tot-1;
 43     while(l <= r) {
 44         mid = (l+r)>>1;
 45         if(arr[mid] == key) return mid;
 46         if(arr[mid] > key) r = mid-1;
 47         else l = mid+1;
 48     }
 49 }
 50
 51 void query(int l, int r, int rt)
 52 {
 53     if(lazy[rt] != -1) {
 54         if(vis[lazy[rt]] == 0)
 55             cnt++;
 56         vis[lazy[rt]] = 1;
 57         return;
 58     }
 59     if(l == r) return;
 60     int mid = (l+r)>>1;
 61     query(l, mid, rt<<1);
 62     query(mid+1, r, rt<<1|1);
 63 }
 64
 65 int main()
 66 {
 67     int i, j, k;
 68     int n, T;
 69     int tot, l, r;
 70     while(scanf("%d", &T) != EOF)
 71     while(T--)
 72     {
 73         memset(vis, 0, sizeof(vis));
 74         memset(lazy, 0xff, sizeof(lazy));
 75         tot = cnt = 0;
 76
 77         scanf("%d", &n);
 78         for(i = 0; i < n; ++i) {
 79             scanf("%d %d", &l, &r);
 80             if(vis[l] == 0){
 81                 vis[l] = 1;
 82                 s[tot++] = l;
 83             }
 84             if(vis[r] == 0) {
 85                 s[tot++] = r;
 86                 vis[r] = 1;
 87             }
 88             node[i].l = l, node[i].r = r;
 89         }
 90
 91         sort(s, s+tot);
 92
 93         for(i = tot-1; i > 0; --i) {
 94             if(s[i] - s[i-1] > 1)
 95                 s[tot++] = s[i-1]+1;
 96         }
 97         sort(s, s+tot);
 98
 99         for(i = 0; i < n; ++i) {
100             l = solve(node[i].l, tot, s);
101             r = solve(node[i].r, tot, s);
102             modify(l, r, i, 0, tot, 1);
103         }
104         memset(vis, 0, sizeof(vis));
105         query(0, tot, 1);
106         printf("%d\n", cnt);
107     }
108     return 0;
109 }