传送门 https://www.luogu.com.cn/problem/P3810
三维偏序, \(\text{CDQ}\) 分治板子题.
判重的地方注意一下, 别的就都是板子了.
参考代码:
- #include <algorithm>
- #include <cstdio>
- #define rg register
- #define file(x) freopen(x".in", "r", stdin), freopen(x".out", "w", stdout)
- using namespace std;
- template <class T> inline void read(T& s) {
- s = 0; int f = 0; char c = getchar();
- while ('0'> c || c> '9') f |= c == '-', c = getchar();
- while ('0' <= c && c <= '9') s = s * 10 + c - 48, c = getchar();
- s = f ? -s : s;
- }
- const int _ = 1e5 + 5, __ = 2e5 + 5;
- int n, k, tr[__], ans[_];
- inline int lb(int x) { return x & -x; }
- inline void update(int x, int v)
- { for (rg int i = x; i <= k; i += lb(i)) tr[i] += v; }
- inline int query(int x)
- { int res = 0; for (rg int i = x; i>= 1; i -= lb(i)) res += tr[i]; return res; }
- struct node { int a, b, c, f, w; } t[_], tt[_];
- inline bool cmp(const node& x, const node& y)
- { return x.a != y.a ? x.a <y.a : (x.b != y.b ? x.b < y.b : x.c < y.c); }
- inline void CDQ(int l, int r) {
- if (l == r) return ;
- int mid = (l + r)>> 1;
- CDQ(l, mid), CDQ(mid + 1, r);
- int i = l, j = mid + 1, p = l;
- while (i <= mid && j <= r) {
- if (t[i].b <= t[j].b)
- update(t[i].c, t[i].w), tt[p++] = t[i++];
- else
- t[j].f += query(t[j].c), tt[p++] = t[j++];
- }
- while (i <= mid) update(t[i].c, t[i].w), tt[p++] = t[i++];
- while (j <= r) t[j].f += query(t[j].c), tt[p++] = t[j++];
- for (rg int i = l; i <= mid; ++i) update(t[i].c, -t[i].w);
- for (rg int i = l; i <= r; ++i) t[i] = tt[i];
- }
- int main() {
- read(n), read(k);
- for (rg int i = 1; i <= n; ++i)
- read(t[i].a), read(t[i].b), read(t[i].c), t[i].w = 1;
- sort(t + 1, t + n + 1, cmp);
- int cnt = 1;
- for (rg int i = 2; i <= n; ++i) {
- if (t[i].a == t[cnt].a && t[i].b == t[cnt].b && t[i].c == t[cnt].c) ++t[cnt].w;
- else t[++cnt] = t[i];
- }
- CDQ(1, cnt);
- for (rg int i = 1; i <= cnt; ++i) ans[t[i].f + t[i].w - 1] += t[i].w;
- for (rg int d = 0; d < n; ++d) printf("%d\n", ans[d]);
- return 0;
- }
来源: http://www.bubuko.com/infodetail-3393609.html