oj.uz

답안 #88901

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
88901 2018-12-09T18:48:06 Z sailormoon Triumphal arch (POI13_luk) C++14
90 / 100
 1135 ms 38124 KB 
#include <string>
#include <algorithm>
#include <iostream>
#include <vector>

using namespace std;
int canHandle(int v, int crs);
vector<vector<int>> graph (1000001); // size
bool visited[1000001];

int main() { 
  int n, a, b, start = 0, midpoint, end, cities; // n -> towns, a -> from, b -> to
  scanf("%d", &n);
  cities = n; // for further usage
  end = n; // last point
  n--;
  while (n--) {
    scanf("%d %d", &a, &b);
    graph[a].push_back(b);
    graph[b].push_back(a);
  }

  // binary search for sufficient amount of crews
  while (start < end) {
    midpoint = (start + end) / 2;
    for (int i = 0; i < cities; i++) visited[i] = false; // clear array 
    if (canHandle(1, midpoint) == 0) end = midpoint;
    else start = midpoint + 1; 
  }
  printf("%d\n", start);
  return 0;
}

int canHandle(int v, int crs) {
  int num_children = 0, need_crews = 0;
  visited[v] = true;
  for (int i = 0; i < graph[v].size(); i++) {
    if (!visited[graph[v][i]]) { 
      num_children++;
      need_crews += canHandle(graph[v][i], crs);
    }
  }
  if (num_children + need_crews - crs <= 0)
    return 0;
  return num_children + need_crews - crs;
}

Compilation message

luk.cpp: In function 'int canHandle(int, int)':
luk.cpp:37:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 0; i < graph[v].size(); i++) {
                   ~~^~~~~~~~~~~~~~~~~
luk.cpp: In function 'int main()':
luk.cpp:13:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &n);
   ~~~~~^~~~~~~~~~
luk.cpp:18:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &a, &b);
     ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 21 ms 23800 KB Output is correct
2 Correct 21 ms 23924 KB Output is correct
3 Correct 22 ms 23992 KB Output is correct

Subtask #2
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 22 ms 23992 KB Output is correct
2 Correct 26 ms 24104 KB Output is correct
3 Correct 25 ms 24104 KB Output is correct
4 Incorrect 22 ms 24104 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #3
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 21 ms 24104 KB Output is correct
2 Correct 23 ms 24104 KB Output is correct
3 Correct 22 ms 24104 KB Output is correct

Subtask #4
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 22 ms 24104 KB Output is correct
2 Correct 22 ms 24104 KB Output is correct
3 Correct 22 ms 24104 KB Output is correct

Subtask #5
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 31 ms 24348 KB Output is correct
2 Correct 30 ms 24684 KB Output is correct
3 Correct 27 ms 24684 KB Output is correct

Subtask #6
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 56 ms 25084 KB Output is correct
2 Correct 56 ms 25792 KB Output is correct
3 Correct 39 ms 25792 KB Output is correct

Subtask #7
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 155 ms 27644 KB Output is correct
2 Correct 143 ms 28924 KB Output is correct
3 Correct 87 ms 28924 KB Output is correct

Subtask #8
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 553 ms 30844 KB Output is correct
2 Correct 584 ms 34284 KB Output is correct
3 Correct 230 ms 34284 KB Output is correct

Subtask #9
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1135 ms 34360 KB Output is correct

Subtask #10
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1070 ms 34428 KB Output is correct
2 Correct 968 ms 38124 KB Output is correct
3 Correct 504 ms 38124 KB Output is correct