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Submission #88847

# Submission time Handle Problem Language Result Execution time Memory
88847 2018-12-09T08:38:39 Z sailormoon Triumphal arch (POI13_luk) C++14
60 / 100
 2000 ms 31784 KB 
#include <map>
#include <string>
#include <algorithm>
#include <iostream>
#include <vector>
#include <set>

using namespace std;

vector<vector<int>> graph (300001); // size
set<int> visited;

int canHandle(int v, int crs) {
    int num_children = 0, need_crews = 0;

    visited.insert(v);

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

int main() { 
    int n, a, b, start = 0, midpoint, end; // n -> towns, a -> from, b -> to
    scanf("%d", &n);
    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;
        if (canHandle(1, midpoint) == 0) 
            end = midpoint;
        else   
            start = ++midpoint; 
        visited.clear();
    }
    printf("%d\n", start);

    return 0;
}

Compilation message

luk.cpp: In function 'int canHandle(int, int)':
luk.cpp:18:23: 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:29:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
luk.cpp:34:14: 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

# Verdict Execution time Memory Grader output
1 Correct 7 ms 7416 KB Output is correct
2 Correct 9 ms 7548 KB Output is correct
3 Correct 7 ms 7548 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 7632 KB Output is correct
2 Correct 7 ms 7632 KB Output is correct
3 Correct 8 ms 7632 KB Output is correct
4 Correct 7 ms 7632 KB Output is correct
5 Correct 10 ms 7632 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 7632 KB Output is correct
2 Correct 8 ms 7632 KB Output is correct
3 Correct 9 ms 7632 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 7632 KB Output is correct
2 Correct 11 ms 7632 KB Output is correct
3 Correct 11 ms 7660 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 77 ms 8428 KB Output is correct
2 Correct 82 ms 8560 KB Output is correct
3 Correct 74 ms 8560 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 394 ms 10092 KB Output is correct
2 Correct 363 ms 10864 KB Output is correct
3 Correct 278 ms 10864 KB Output is correct

Subtask #7
0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 2094 ms 15820 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 2029 ms 23720 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 2029 ms 31784 KB Time limit exceeded

Subtask #10
0 / 10.0

# Verdict Execution time Memory Grader output
1 Execution timed out 2061 ms 31784 KB Time limit exceeded
2 Halted 0 ms 0 KB -