9.5训练赛 D: Gym 102152B

思路:
差分对区间进行 O ( n ) O(n) O(n)处理标记区间,分块取出每一块的数量和边界 r r r,对每一块的数量进行排序,二分出符合x询问的边界值,建立线段树对该区间进行最大值询问。

注意:写线段树时,注意 n = 0 n=0 n=0 的情况

参考代码:

/*
 * @Author: vain
 * @Date: 2020-08-26 11:58:46
 * @LastEditTime: 2020-09-06 10:33:18
 * @LastEditors: sueRimn
 * @Description: In User Settings Edit
 * @FilePath: \main\demo.cpp
 */
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
using namespace std;
typedef long long ll;
//#define ll long long
typedef unsigned long long ull;
const ll N = 2e3 + 20;
const ll maxn = 1e5 + 20;
const ll mod = 1e9 + 7;
ll head[maxn], stac[maxn];
int a[maxn], b[maxn], c[maxn];
//typedef pair p;
//priority_queue, greater

> m; //ll sum[maxn]; int max(int a, int b) { return a > b ? a : b; } ll min(ll a, ll b) { return a < b ? a : b; } ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; } ll lcm(ll a, ll b) { return a * b / gcd(a, b); } void swap(ll &x, ll &y) { x ^= y, y ^= x, x ^= y; } map<string, ll> pll, che, mp; ll f[N][3], q[N]; int lowbit(int x) { return (x) & (-x); } vector<int> fc; //ull h[maxn], p[maxn]; const ull base = 13331; //char s1[maxn]; ll ksm(ll a, ll b) { ll res = 1; while (b) { if (b & 1) res = a * res; b >>= 1; a = a * a; } return res; } struct node { int r, sizx; } p[maxn]; bool cmp(node x, node y) { return x.sizx < y.sizx; } struct vain { int l, r, ma; } tr[maxn << 2]; int pushup(int k) { tr[k].ma = max(tr[k << 1].ma, tr[k << 1 | 1].ma); } void build(int k, int l, int r) { tr[k].l = l, tr[k].r = r; if (l == r) { tr[k].ma = p[l].r; return; } int mid = l + r >> 1; build(k << 1, l, mid); build(k << 1 | 1, mid + 1, r); pushup(k); } int query(int k, int ql, int qr) { if (tr[k].l >= ql && tr[k].r <= qr) { return tr[k].ma; } int mid = tr[k].l + tr[k].r >> 1; int ans = 0; if (ql <= mid) { ans = max(ans, query(k << 1, ql, qr)); } if (qr > mid) { ans = max(ans, query(k << 1 | 1, ql, qr)); } return ans; } int main() { // ios::sync_with_stdio(false); // cin.tie(0), cout.tie(0); // srand(time(NULL)); int n, m, t, s, q; scanf("%d", &t); while (t--) { fc.clear(); scanf("%d %d %d", &n, &m, &q); for (int i = 0; i <= m; i++) a[i] = 0; while (n--) { int l, r; scanf("%d %d", &l, &r); a[l]--; a[r + 1]++; } for (int i = 1; i <= m; i++) a[i] = a[i] + a[i - 1]; int cnt = 0, ans = 0; for (int i = 1; i <= m; i++) { if (!a[i]) ans++; else if (ans) p[++cnt].sizx = ans, p[cnt].r = i - 1, ans = 0; } if (ans) p[++cnt].sizx = ans, p[cnt].r = m; sort(p + 1, p + 1 + cnt, cmp); for (int i = 1; i <= cnt; i++) fc.push_back(p[i].sizx); if (cnt > 0) build(1, 1, cnt); while (q--) { int x; scanf("%d", &x); if (x > p[cnt].sizx) printf("-1 -1\n"); else { int y = lower_bound(fc.begin(), fc.end(), x) - fc.begin() + 1; int qr = query(1, y, cnt); printf("%d %d\n", qr - x + 1, qr); } } } }

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