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| #include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
using namespace std;
const int N = 10010;
int c, n, l, r;
pair<int, int> pos[N];
vector<int> s;
int get(int x) {
return lower_bound(s.begin(), s.end(), x) - s.begin();
}
struct Node {
int l, r, lazy;
} t[N << 3];
void build(int u, int l, int r) {
t[u] = {l, r, 0};
if (l == r) return;
int mid = l + r >> 1;
build(u << 1, l, mid), build(u << 1 | 1, mid + 1, r);
}
bool update(int u, int l, int r) {
if (t[u].lazy) return false;
if (t[u].l == t[u].r) return t[u].lazy = true;
bool res = false;
int mid = t[u].l + t[u].r >> 1;
if (l <= mid) res |= update(u << 1, l, r);
if (r > mid) res |= update(u << 1 | 1, l, r);
if (t[u << 1].lazy && t[u << 1 | 1].lazy) t[u].lazy = true;
return res;
}
int main() {
scanf("%d", &c);
while (c--) {
s.clear();
memset(t, 0, sizeof(t));
scanf("%d", &n);
for (int i = 1; i <= n; ++i) {
scanf("%d%d", &l, &r);
++r;
pos[i] = {l, r};
s.push_back(l);
s.push_back(r);
}
sort(s.begin(), s.end());
s.erase(unique(s.begin(), s.end()), s.end());
int len = s.size();
build(1, 0, s.size() - 2);
int ans = 0;
for (int i = n; i; --i) {
l = get(pos[i].first), r = get(pos[i].second) - 1;
if (update(1, l, r)) ++ans;
}
printf("%d\n", ans);
}
return 0;
}
|