Submission #1116419

#	Time	Username	Problem	Language	Result	Execution time	Memory
1116419		ntdaccode	Cat Exercise (JOI23_ho_t4)	C++17	41 / 100	91 ms	53428 KiB

Main

#include<bits/stdc++.h>
#define fori(i,a,b) for(int i = a;i <= b; i++)
#define int long long
#define pb push_back

using namespace std;

typedef pair<int,int> ii;
typedef tuple<int,int,int> tp;

const int M = 1e6 + 10;
const int N = 1e3 + 10;
const int mod = 1e9 + 7;

int n,p[M];

int ma[M][20],lg[M];
int getmax(int l,int r)
{
   int k = lg[r - l + 1];
   int u = ma[l][k];
   int v = ma[r - (1<<k) +1][k];
   if(p[u] > p[v]) return u;
   return v;
}

int f[M],pos[M],cnt = 0;
int solve(int l,int r)
{
   //cout << l << " " << r <<    "\n";
   if(l > r) return -1;
   cnt++;
   int cur = cnt;
   pos[cur] = getmax(l,r);
   //cout << l << " " << r << " " << pos[cur] <<   "\n";
   int pre = solve(l,pos[cur] - 1);
   int nxt = solve(pos[cur] + 1,r);
   if(pre != -1) f[cur] = max(f[cur],f[pre] + abs(pos[cur] - pos[pre]));
   if(nxt != -1) f[cur] = max(f[cur],f[nxt] + abs(pos[cur] - pos[nxt]));
    //cout << l << " " << r << " " << f[cur] << "sa\n";
   return cur;
}

int32_t main()
{
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  if(fopen("1.inp","r"))
  {
    freopen("1.inp","r",stdin);
    freopen("1.out","w",stdout);
  }
  #define task ""
  if(fopen(task".inp","r"))
  {
    freopen(task".inp","r",stdin);
    freopen(task".out","w",stdout);
  }
  cin >> n ;
  for(int i = 1;i <= n; i++) cin >> p[i],ma[i][0] = i;
  for(int i = 1;i <= n - 1; i++) {
      int u,v;
      cin >> u >> v;
  }
  for(int i = 1;i <= 18; i++) {
      for(int j = 1;j + (1<<i) - 1 <= n; j++) {
            int u = ma[j][i - 1];
            int v = ma[j + (1 << i-1)][i - 1];
            if(p[u] > p[v]) ma[j][i] = u;
            else ma[j][i] = v;
      }
  }
  for(int i = 1;i <= n; i++) lg[i]= __lg(i);
  solve(1,n);
  cout << f[1] ;


}

Compilation message (stderr)

Main.cpp: In function 'int32_t main()':
Main.cpp:69:35: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   69 |             int v = ma[j + (1 << i-1)][i - 1];
      |                                  ~^~
Main.cpp:51:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |     freopen("1.inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~
Main.cpp:52:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |     freopen("1.out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~
Main.cpp:57:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |     freopen(task".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
Main.cpp:58:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   58 |     freopen(task".out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 7 / 7
• Subtask 4: 0 / 10
• Subtask 5: 20 / 20
• Subtask 6: 0 / 23
• Subtask 7: 0 / 26