Submission #736034

# Submission time Handle Problem Language Result Execution time Memory
736034 2023-05-05T06:55:23 Z math_rabbit_1028 Radio Towers (IOI22_towers) C++17
0 / 100
318 ms 9884 KB
#include "towers.h"
#include <bits/stdc++.h>
using namespace std;
 
int n;
vector<int> arr;
vector<int> upidx, downidx;

struct localmax {
  int idx, d, l, r;
  bool operator<(const localmax &other) const {
    return d < other.d;
  }
  void update() {
    d = arr[upidx[idx]] - max(arr[l], arr[r]);
  } 
} local_value[101010];
int adj[101010][2];
set<localmax> local;

vector< pair<int, int> > Dlist;

void init(int N, vector<int> H) {
  n = N;
  for (int i = 0; i < N; i++) arr.push_back(H[i]);
  
  if (arr[0] < arr[1]) downidx.push_back(0);
  for (int i = 1; i < N - 1; i++) {
    if (arr[i] > arr[i - 1] && arr[i] > arr[i + 1]) upidx.push_back(i);
    if (arr[i] < arr[i - 1] && arr[i] < arr[i + 1]) downidx.push_back(i);
  }
  if (arr[N - 1] < arr[N - 2]) downidx.push_back(N - 1);
  
  for (int i = 0; i < upidx.size(); i++) {
    local_value[i] = {i, 0, downidx[i], downidx[i + 1]};
    local_value[i].update();
    local.insert(local_value[i]);
    adj[i][0] = i - 1;
    adj[i][1] = i + 1;
  }

  while (!local.empty()) {
    localmax now = *local.begin();
    Dlist.push_back({now.d, upidx[now.idx]});
    int next = (arr[now.l] < arr[now.r] ? now.l : now.r);
    local.erase(local.begin());
    if (adj[now.idx][0] >= 0) {
      set<localmax>::iterator iter = local.find(local_value[adj[now.idx][0]]);
      local.erase(iter);
      local_value[adj[now.idx][0]].r = next;
      local_value[adj[now.idx][0]].update();
      local.insert(local_value[adj[now.idx][0]]);
      adj[adj[now.idx][0]][1] = adj[now.idx][1];
    }
    if (adj[now.idx][1] < upidx.size()) {
      set<localmax>::iterator iter = local.find(local_value[adj[now.idx][1]]);
      local.erase(iter);
      local_value[adj[now.idx][1]].l = next;
      local_value[adj[now.idx][1]].update();
      local.insert(local_value[adj[now.idx][1]]);
      adj[adj[now.idx][1]][0] = adj[now.idx][0];
    }
  }

  // for (int i = 0; i < Dlist.size(); i++) cout << Dlist[i].first << " " << Dlist[i].second << "\n";

}
 
int max_towers(int L, int R, int D) {
  int ans = Dlist.end() - lower_bound(Dlist.begin(), Dlist.end(), make_pair(D, 0)) + 1;
  return ans;
}

Compilation message

towers.cpp: In function 'void init(int, std::vector<int>)':
towers.cpp:34:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |   for (int i = 0; i < upidx.size(); i++) {
      |                   ~~^~~~~~~~~~~~~~
towers.cpp:55:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |     if (adj[now.idx][1] < upidx.size()) {
      |         ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Incorrect 318 ms 1104 KB 1st lines differ - on the 1st token, expected: '1', found: '2'
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 336 KB 1st lines differ - on the 1st token, expected: '13', found: '131'
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 336 KB 1st lines differ - on the 1st token, expected: '13', found: '131'
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 36 ms 9548 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 231 ms 1472 KB Output is correct
2 Runtime error 40 ms 9884 KB Execution killed with signal 6
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 336 KB 1st lines differ - on the 1st token, expected: '13', found: '131'
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 318 ms 1104 KB 1st lines differ - on the 1st token, expected: '1', found: '2'
2 Halted 0 ms 0 KB -