oj.uz

답안 #600123

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
600123 2022-07-20T13:21:19 Z MilosMilutinovic 코끼리 (Dancing Elephants) (IOI11_elephants) C++14
50 / 100
 5699 ms 3208 KB 
/**
 *    author:  wxhtzdy
 *    created: 20.07.2022 11:59:55
**/
#include "elephants.h"
#include <bits/stdc++.h>

using namespace std;

const int MAX = 150005;
const int BLOCK = sqrt(MAX);

int n, l, x[MAX], cnt[MAX], pos[MAX];
int id[MAX], order[MAX];

vector<int> idx[MAX / BLOCK + 5];

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--) {
    assert(id[idx[i][j]] == i);
    if (j + 1 < sz) {
      assert(x[idx[i][j]] <= x[idx[i][j + 1]]);
    }
    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;

bool first = true;

int update(int i, int y) {
  ++Q;
  x[i] = y;
  if (Q == BLOCK / 7) {
    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]] <= x[i]) {
        id[i] = j;
        break;
      } 
    }        
    idx[id[i]].push_back(i);
    /*if (idx[id[i]].empty() || x[idx[id[i]].back()] < y) {
    } 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]);
  } 
  int lst = -1;       
  for (int j = 0; j <= n / BLOCK; j++) {
    if (idx[j].empty()) {
      continue;
    }
    assert(lst <= x[idx[j][0]]);
    lst = x[idx[j].back()];
  }
  //Build(); // brute force check
  int ans = 0, R = -1;
  for (int j = 0; j <= n / BLOCK; j++) {
    if (idx[j].empty() || x[idx[j].back()] <= R) {
      continue;
    }                                          
    int low = 0, high = (int) idx[j].size() - 1, at = 0;
    while (low <= high) {
      int mid = low + high >> 1;
      if (x[idx[j][mid]] > R) {
        at = mid;
        high = mid - 1;
      } else {
        low = mid + 1;
      }
    }
    assert(R < x[idx[j][at]] && (at == 0 || R >= x[idx[j][at - 1]]));
    ans += cnt[idx[j][at]];
    R = pos[idx[j][at]];
  }
  if (false) {
    for (int i = 0; i < n; i++) {
      order[i] = i;
    }
    sort(order, order + n, [&](int i, int j) {
      return x[i] < x[j];
    });     
    int nans = 0;
    for (int i = 0; i < n; i++) {
      int ptr = i;
      while (ptr + 1 < n && x[order[ptr + 1]] <= x[order[i]] + l) {
        ptr += 1;
      }
      i = ptr;
      nans += 1;
    }
    assert(nans == ans);
    first = false;
  }  
  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:132:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  132 |       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 1 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 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 0 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 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 0 ms 340 KB Output is correct
7 Correct 1693 ms 1288 KB Output is correct
8 Correct 1892 ms 1460 KB Output is correct
9 Correct 3090 ms 2356 KB Output is correct
10 Correct 3219 ms 2360 KB Output is correct
11 Correct 3207 ms 2356 KB Output is correct
12 Correct 5699 ms 2356 KB Output is correct
13 Correct 3176 ms 2260 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 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 0 ms 340 KB Output is correct
7 Correct 1693 ms 1288 KB Output is correct
8 Correct 1892 ms 1460 KB Output is correct
9 Correct 3090 ms 2356 KB Output is correct
10 Correct 3219 ms 2360 KB Output is correct
11 Correct 3207 ms 2356 KB Output is correct
12 Correct 5699 ms 2356 KB Output is correct
13 Correct 3176 ms 2260 KB Output is correct
14 Runtime error 2413 ms 3208 KB Execution killed with signal 6
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 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 0 ms 340 KB Output is correct
7 Correct 1693 ms 1288 KB Output is correct
8 Correct 1892 ms 1460 KB Output is correct
9 Correct 3090 ms 2356 KB Output is correct
10 Correct 3219 ms 2360 KB Output is correct
11 Correct 3207 ms 2356 KB Output is correct
12 Correct 5699 ms 2356 KB Output is correct
13 Correct 3176 ms 2260 KB Output is correct
14 Runtime error 2413 ms 3208 KB Execution killed with signal 6
15 Halted 0 ms 0 KB -