2020 ccpc QHD重现 E、K

Exam Results

双指针写法

/*
 *@author spnooyseed
 */
#pragma GCC optimize("Ofast","unroll-loops","omit-frame-pointer","inline")
#pragma GCC optimize(3 , "Ofast" , "inline")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimization("unroll-loops")
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
using namespace std ;
#define ios ios::sync_with_stdio(false) , cin.tie(0)
#define x first
#define y second
#define pb push_back
#define ls rt << 1
#define rs rt << 1 | 1
typedef long long ll ;
const double esp = 1e-6 , pi = acos(-1) ;
typedef pair PII ;
const int N = 1e6 + 10 , INF = 0x3f3f3f3f , mod = 1e9 + 7;
PII a[N] ;
int ca = 0 , b[N] ;
vector v ;
int work()
{
  int n , p ;
  cin >> n >> p ;
  v.clear() ;
  for(int i = 1; i <= n ;i ++ ) {
    cin >> a[i].x >> a[i].y ;
    v.push_back({a[i].x , i}) ;
    v.push_back({a[i].y , i}) ;
    if(a[i].x > a[i].y) swap(a[i].x , a[i].y) ;
  }
  sort(v.begin() , v.end()) ;
  sort(a + 1 , a + n + 1) ;
  for(int i = 1; i <= n ;i ++ ) b[i] = 0 ;
  int cnt = 0 , ans = 0 ;
  for(int r = 0 , l = 0 ;r < v.size() ; r ++ ) {
    b[v[r].y] ++ ;
    if(b[v[r].y] == 1) cnt ++ ;
    if(v[r].x < a[n].x) continue ;
    ll xx = v[r].x * p ;
    while(l < v.size() && 1ll * v[l].x * 100 < xx) {
      b[v[l].y] -- ;
      if(b[v[l].y] == 0) cnt -- ;
      l ++ ;
    }
    ans = max(ans , cnt) ;
  }
  cout << "Case #" << ++ ca << ": " << ans << endl ;
  return 0 ;
}
int main()
{
  //   freopen("C://Users//spnooyseed//Desktop//in.txt" , "r" , stdin) ;
  //   freopen("C://Users//spnooyseed//Desktop//out.txt" , "w" , stdout) ;
  int n ;
  cin >> n ;
  while(n --)
  work() ;
  return 0 ;
}
/*
*/

主席树加二分

/*
 *@author spnooyseed
 */
#pragma GCC optimize("Ofast","unroll-loops","omit-frame-pointer","inline")
#pragma GCC optimize(3 , "Ofast" , "inline")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimization("unroll-loops")
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
using namespace std ;
#define ios ios::sync_with_stdio(false) , cin.tie(0)
#define x first
#define y second
#define pb push_back
#define ls rt << 1
#define rs rt << 1 | 1
typedef long long ll ;
const double esp = 1e-6 , pi = acos(-1) ;
typedef pair PII ;
const int N = 2e5 + 10 , INF = 0x3f3f3f3f , mod = 1e9 + 7;
int ca = 0 ;
PII a[N] ;
ll b[N] , c[N] ;
int root[N * 45] , tot ;
struct node {
  int l , r , sum ;
}t[N * 45] ;
void build(int &now , int l , int r){
  t[now = ++ tot].sum = 0 ;
  if(l == r) return ;
  int mid = l + r >> 1 ;
  build(t[now].l , l , mid) ;
  build(t[now].r , mid + 1 , r) ;
  return ;
}
void up(int now){
  t[now].sum = t[t[now].l].sum + t[t[now].r].sum ;
}
void update(int &now , int last , int l , int r , int pos){
  t[now = ++ tot] = t[last] ;
  if(l == r) {
    t[now].sum ++ ;
    return ;
  }
  int mid = l + r >> 1 ;
  if(pos <= mid) update(t[now].l , t[last].l , l , mid , pos) ;
  else update(t[now].r , t[last].r , mid + 1 , r , pos) ;
  up(now) ;
  return ;
}
int ask(int now , int last , int l , int r , int k){
  if(!k) return 0 ;
  if(r <= k) return t[now].sum - t[last].sum ;
  int mid = l + r >> 1 , ans = 0 ;
  if(k <= mid) ans += ask(t[now].l , t[last].l , l , mid , k) ;
  else ans += ask(t[now].l , t[last].l  , l , mid , k) + ask(t[now].r , t[last].r , mid + 1 , r , k) ;
  return ans ;
}
ll d[N] ;
int work()
{
  int n , p , cnt = 0;
  scanf("%d%d" , &n , &p) ;
  tot = 0 ;
  for(int i = 1; i <= n ;i ++ ) {
    scanf("%lld%lld" , &a[i].x , &a[i].y) ;
    a[i].x *= 100l , a[i].y *= 100l ;
    if(a[i].x > a[i].y) swap(a[i].x , a[i].y) ;
  }

  sort(a + 1 , a + n + 1) ;
  for(int i = 1; i <= n ;i ++ ) c[i] = a[i].x ;
  c[n + 1] = 1e12 ;
  for(int i = 1; i <= n ;i ++ ) {
    if(a[i].x >= a[n].x) b[++ cnt] = a[i].x ;
    if(a[i].y >= a[n].x) b[++ cnt] = a[i].y ;
  }
  sort(b + 1 , b + cnt + 1) ;
  for(int i = 1; i <= n ;i ++ ) d[i] = a[i].y ;
  sort(d + 1 , d + n + 1) ;
  d[n + 1] = 1e12 ;
  for(int i = 1; i <= n ;i ++ )
   a[i].y = lower_bound(d + 1 , d + n + 1 , a[i].y) - d ;
  build(root[0] , 1 , n) ;
  for(int i = 1; i <= n ;i ++ )
   update(root[i] , root[i - 1] , 1 , n , a[i].y) ;
  ll ans = 0 ;
  for(int i = 1; i <= cnt; i ++ ) {
    ll x = b[i] / 100l ;
    ll t = lower_bound(c + 1 , c + n + 1  , 1ll * x * p) - c;
    ll y1 = lower_bound(d + 1 , d + n + 1 , 1ll * b[i]) - d ;
    y1 = min(1ll * n , y1) ;
    if(d[y1] > b[i]) y1 -- ;
    ll y2 = upper_bound(d + 1 , d + n + 1 , 1ll * x * p - 1) - d - 1 ;
    ll res = 0 ;
    if(t - 1 > 0)
     res = ask(root[t - 1] , root[0] , 1 , n , y1) - ask(root[t - 1] , root[0] , 1 , n , y2) ;
    ans = max(ans , n - t + 1 + res) ;
  }
  cout << "Case #" << ++ ca << ": " << ans << endl ;
  return 0 ;
}
int main()
{
  //   freopen("C://Users//spnooyseed//Desktop//in2.txt" , "r" , stdin) ;
  //   freopen("C://Users//spnooyseed//Desktop//out.txt" , "w" , stdout) ;
  int n ;
  cin >> n ;
  while(n --)
  work() ;
  return 0 ;
}
/*
1
9 97
564 6736
3658 28141
4595 16759
5441 28611
7014 30529
14225 26768
15885 24472
20431 25127
21544 32369
*/

Kingdom's Power

树形dp

/*
 *@author spnooyseed
 */
#pragma GCC optimize("Ofast","unroll-loops","omit-frame-pointer","inline")
#pragma GCC optimize(3 , "Ofast" , "inline")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimization("unroll-loops")
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
using namespace std ;
#define ios ios::sync_with_stdio(false) , cin.tie(0)
#define x first
#define y second
#define pb push_back
#define ls rt << 1
#define rs rt << 1 | 1
typedef long long ll ;
const double esp = 1e-6 , pi = acos(-1) ;
typedef pair PII ;
const int N = 1e6 + 10 , INF = 0x3f3f3f3f , mod = 1e9 + 7;
vector v[N] ;
int deep[N] ;
void dfs(int u) {
  int maxn = 0 ;
  for(auto x : v[u]) {
    dfs(x) ;
    maxn = max(maxn , deep[x]) ;
  }
  deep[u] = maxn + 1 ;
  return ;
}
bool cmp(int a , int b) {
  return deep[a] < deep[b] ;
}
int ca = 0 ;
int a[N] ;
ll dfs(int u , int f , int dep) {
  a[u] = a[f] + 1 ;
  ll maxn = a[u] ;
  for(int i = 0 ;i < v[u].size() ;i ++ ) {
    int x = v[u][i] ;
    if(x == f) continue ;
    maxn = max(maxn , dfs(x , u , dep + 1));
    if(i != v[u].size() - 1)
    a[u] = maxn + min(deep[x] , dep);
  }
  return maxn ;
}
int work()
{
  int n ;
  scanf("%d" , &n) ;
  for(int i = 1; i <= n ; i ++ ) v[i].clear() ;
  for(int i = 2; i <= n ;i ++ ) {
    int x ;
    scanf("%d" , &x) ;
    v[x].push_back(i) ;
  }
  dfs(1) ;
  for(int i = 1; i <= n ;i ++ )
   if(v[i].size())
    sort(v[i].begin() , v[i].end() , cmp) ;
  ll ans = 0 ;
  for(auto x : v[1])
    ans += 1ll * dfs(x , 1 , 1) ;
  cout << "Case #" << ++ ca << ": " << ans << endl ;
  return 0 ;
}
int main()
{
  //   freopen("C://Users//spnooyseed//Desktop//in.txt" , "r" , stdin) ;
  //   freopen("C://Users//spnooyseed//Desktop//out.txt" , "w" , stdout) ;
  int n ;
  cin >> n ;
  while(n --)
  work() ;
  return 0 ;
}
/*
1
15
1 2 3 3 2 6 1 8 8 9 10 10 10 8
Case #1: 20
*/
CCPC双指针主席树树形dp

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