oj.uz

답안 #600045

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
600045 2022-07-20T12:10:03 Z MilosMilutinovic 코끼리 (Dancing Elephants) (IOI11_elephants) C++14
50 / 100
 4188 ms 2368 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) {
  sort(idx[i].begin(), idx[i].end(), [&](int a, int b) {
    if (x[a] != x[b]) {
      return x[a] < x[b];
    } else {
      return a < b;
    }
  });
  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) {
    if (x[i] != x[j]) {
      return x[i] < x[j];
    } else {
      return i < 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 <= n / BLOCK; i++) {
    BuildBlock(i);
  }
}

int Q;

int update(int i, int y) {
  ++Q;
  x[i] = y;
  if (Q == BLOCK / 5) {
    Build();
    Q = 0;
  } else {
    vector<int> b;
    bool found = false;
    for (int j = 0; j < (int) idx[id[i]].size(); j++) {
      if (idx[id[i]][j] != i) {      
        b.push_back(idx[id[i]][j]);
      } else {
        found = true;
      }
    }
    assert(found);
    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;
      }
    }
    assert(R < x[idx[i][at]] && (at == 0 || R >= x[idx[i][at - 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:118:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  118 |       int mid = low + high >> 1;
      |                 ~~~~^~~~~~

Subtask #1
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 0 ms 340 KB Output is correct

Subtask #2
16.0 / 16.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 0 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

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 0 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 1199 ms 1288 KB Output is correct
8 Correct 1352 ms 1436 KB Output is correct
9 Correct 2178 ms 2368 KB Output is correct
10 Correct 2469 ms 2360 KB Output is correct
11 Correct 2544 ms 2360 KB Output is correct
12 Correct 4188 ms 2368 KB Output is correct
13 Correct 2436 ms 2360 KB Output is correct

Subtask #4
0 / 47.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 0 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 1199 ms 1288 KB Output is correct
8 Correct 1352 ms 1436 KB Output is correct
9 Correct 2178 ms 2368 KB Output is correct
10 Correct 2469 ms 2360 KB Output is correct
11 Correct 2544 ms 2360 KB Output is correct
12 Correct 4188 ms 2368 KB Output is correct
13 Correct 2436 ms 2360 KB Output is correct
14 Incorrect 1783 ms 1796 KB Output isn't correct
15 Halted 0 ms 0 KB -

Subtask #5
0 / 3.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 0 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 1199 ms 1288 KB Output is correct
8 Correct 1352 ms 1436 KB Output is correct
9 Correct 2178 ms 2368 KB Output is correct
10 Correct 2469 ms 2360 KB Output is correct
11 Correct 2544 ms 2360 KB Output is correct
12 Correct 4188 ms 2368 KB Output is correct
13 Correct 2436 ms 2360 KB Output is correct
14 Incorrect 1783 ms 1796 KB Output isn't correct
15 Halted 0 ms 0 KB -