oj.uz

Submission #600002

# Submission time Handle Problem Language Result Execution time Memory
600002 2022-07-20T11:29:22 Z MilosMilutinovic Dancing Elephants (IOI11_elephants) C++14
50 / 100
 1936 ms 2380 KB 
/**
 *    author:  wxhtzdy
 *    created: 20.07.2022 11:59:55
**/
#include "elephants.h"
#include <bits/stdc++.h>
 
using namespace std;
 
const int N = 150005;
const int BLOCK = sqrt(N);
 
int n, l, x[N], cnt[N], pos[N];
int id[N], order[N];
 
vector<int> idx[N / BLOCK];
 
void BuildBlock(int i) {
  int sz = (int) idx[i].size();
  int ptr = sz - 1;    
  for (int j = sz - 1; j >= 0; j--) {
    if (x[idx[i][sz - 1]] - x[idx[i][j]] <= l) {
      cnt[idx[i][j]] = 1;
      pos[idx[i][j]] = x[idx[i][j]] + l;
    } else { 
      while (x[idx[i][ptr]] - x[idx[i][j]] > l) {
        ptr -= 1;
      }
      cnt[idx[i][j]] = cnt[idx[i][ptr + 1]] + 1;
      pos[idx[i][j]] = pos[idx[i][ptr + 1]];
    }                              
  }
}
 
void Build() {     
  for (int i = 0; i < n; i++) {
    order[i] = i;
  }
  sort(order, order + n, [&](int i, int j) {
    return x[i] < x[j];
  });
  for (int i = 0; i <= n / BLOCK; i++) {
    idx[i].clear();
  }
  for (int i = 0; i < n; i++) {
    id[order[i]] = i / BLOCK;
    idx[id[order[i]]].push_back(order[i]);
  }
  for (int i = 0; i <= id[order[n - 1]]; i++) {
    BuildBlock(i);
  }
}
 
int Q;
 
int update(int i, int y) {
  ++Q;
  x[i] = y;
  if (Q == BLOCK / 2) {
    Build();
    Q = 0;
  } else {
    vector<int> b;
    for (int j = 0; j < (int) idx[id[i]].size(); j++) {
      if (idx[id[i]][j] != i) {      
        b.push_back(idx[id[i]][j]);
      }
    }
    idx[id[i]] = b;
    BuildBlock(id[i]);
    b.clear();
    for (int j = n / BLOCK; j >= 0; j--) {
      if (!idx[j].empty() && x[idx[j][0]] <= y) {
        id[i] = j;
        break;
      } 
    }        
    if (idx[id[i]].empty() || x[idx[id[i]].back()] < y) {
      idx[id[i]].push_back(i);
    } else {
      vector<int> b;    
      for (int j = 0; j < (int) idx[id[i]].size(); j++) {
        if (y <= x[idx[id[i]][j]]) {
          b.push_back(i);
          y = (int) 1.01e9;
          j -= 1;
        } else {
          b.push_back(idx[id[i]][j]);
        }
      }
      idx[id[i]] = b;
    }
    BuildBlock(id[i]);
  } 
  //Build(); // brute force check
  int ans = 0, R = -1;
  for (int i = 0; i <= n / BLOCK; i++) {
    if (idx[i].empty() || x[idx[i].back()] <= R) {
      continue;
    }                                          
    int low = 0, high = (int) idx[i].size() - 1, at = 0;
    while (low <= high) {
      int mid = low + high >> 1;
      if (x[idx[i][mid]] > R) {
        at = mid;
        high = mid - 1;
      } else {
        low = mid + 1;
      }
    }
    ans += cnt[idx[i][at]];
    R = pos[idx[i][at]];
  }       
  return ans; 
}
 
void init(int n, int l, int x[]) {
  ::n = n;
  ::l = l;
  for (int i = 0; i < n; i++) {
    ::x[i] = x[i];
  }
  Build();
}

Compilation message

elephants.cpp: In function 'int update(int, int)':
elephants.cpp:103:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  103 |       int mid = low + high >> 1;
      |                 ~~~~^~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct

Subtask #2
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 601 ms 1288 KB Output is correct
8 Correct 638 ms 1428 KB Output is correct
9 Correct 973 ms 2364 KB Output is correct
10 Correct 1061 ms 2360 KB Output is correct
11 Correct 978 ms 2364 KB Output is correct
12 Correct 1936 ms 2380 KB Output is correct
13 Correct 1016 ms 2364 KB Output is correct

Subtask #4
0 / 47.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 601 ms 1288 KB Output is correct
8 Correct 638 ms 1428 KB Output is correct
9 Correct 973 ms 2364 KB Output is correct
10 Correct 1061 ms 2360 KB Output is correct
11 Correct 978 ms 2364 KB Output is correct
12 Correct 1936 ms 2380 KB Output is correct
13 Correct 1016 ms 2364 KB Output is correct
14 Incorrect 245 ms 1688 KB Output isn't correct
15 Halted 0 ms 0 KB -

Subtask #5
0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 601 ms 1288 KB Output is correct
8 Correct 638 ms 1428 KB Output is correct
9 Correct 973 ms 2364 KB Output is correct
10 Correct 1061 ms 2360 KB Output is correct
11 Correct 978 ms 2364 KB Output is correct
12 Correct 1936 ms 2380 KB Output is correct
13 Correct 1016 ms 2364 KB Output is correct
14 Incorrect 245 ms 1688 KB Output isn't correct
15 Halted 0 ms 0 KB -