离散化搞下。就是8 9 19 分别映射到 1 2 3 上。用map好像会超时，可能自己写戳了。
#include <cstdio> #include <cstring> #include <algorithm> #include <climits> #include <string> #include <iostream> #include <map> #include <cstdlib> #include <list> #include <set> #include <queue> #include <stack> #include<math.h> using namespace std; #define lson l,mid,rt<<1 #define rson mid+1,r,rt<<1|1 const int maxn = 44444; int color[maxn << 2]; int vis[maxn]; int q[maxn]; int q1[maxn]; int l[maxn]; int r[maxn]; int Hash[maxn]; void down(int rt) { if (color[rt]){ color[rt << 1] = color[rt << 1 | 1] = color[rt]; color[rt] = 0; } } void build(int l, int r, int rt) { color[rt] = 0; if (l == r) return; int mid = (l + r) >> 1; build(lson); build(rson); } void update(int L, int R, int add, int l, int r, int rt) { if (L <= l&&r <= R){ color[rt] = add; return; } down(rt); int mid = (l + r) >> 1; if (L <= mid) update(L, R, add, lson); if (R>mid) update(L, R, add, rson); } void ask(int l, int r, int rt) { if (color[rt]){ Hash[color[rt]] = 1; return; } int mid = (l + r) >> 1; ask(lson); ask(rson); } int erfen(int key, int a[], int len) { int l = 0; int r = len - 1; while (l <= r){ int mid = (l + r) >> 1; if (a[mid] == key) return mid + 1; if (a[mid]<key) l = mid + 1; if (a[mid]>key) r = mid - 1; } } int cmp(const int &a, const int &b) { return a<b; } int main() { int Icase, n; int ans, ans1; scanf("%d", &Icase); while (Icase--){ ans = 0; ans1 = 0; memset(Hash, 0, sizeof(Hash)); scanf("%d", &n); for (int i = 0; i<n; i++){ scanf("%d%d", &l[i], &r[i]); q[ans++] = l[i]; q[ans++] = r[i]; } sort(q, q + ans, cmp); memset(vis, 0, sizeof(vis)); for (int i = 0; i<ans - 1; i++){ if (q[i] == q[i + 1]) vis[i + 1] = 1; } int ans1 = 0; for (int i = 0; i<ans; i++) if (!vis[i]) q1[ans1++] = q[i]; for (int i = 0; i<n; i++){ l[i] = erfen(l[i], q1, ans1); r[i] = erfen(r[i], q1, ans1); } build(1, ans1, 1); for (int i = 0; i<n; i++){ update(l[i], r[i], i + 1, 1, ans1, 1); } ask(1, ans1, 1); int gg = 0; for (int i = 1; i <= n; i++) if (Hash[i]) gg++; cout << gg << endl; } return 0; }