oj.uz

Submission #88876

# Submission time Handle Problem Language Result Execution time Memory
88876 2018-12-09T17:07:10 Z sailormoon Triumphal arch (POI13_luk) C++14
90 / 100
 1417 ms 38172 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);
        }
    }
    return max(0, num_children + need_crews - crs);
}

Compilation message

luk.cpp: In function 'int canHandle(int, int)':
luk.cpp:44:23: 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:14:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
luk.cpp:20:14: 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 22 ms 23800 KB Output is correct
2 Correct 22 ms 23984 KB Output is correct
3 Correct 22 ms 23984 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 23984 KB Output is correct
2 Correct 22 ms 23984 KB Output is correct
3 Correct 23 ms 23984 KB Output is correct
4 Incorrect 23 ms 23984 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 30 ms 23984 KB Output is correct
2 Correct 25 ms 23984 KB Output is correct
3 Correct 25 ms 23984 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 27 ms 23984 KB Output is correct
2 Correct 26 ms 24092 KB Output is correct
3 Correct 25 ms 24092 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 24424 KB Output is correct
2 Correct 35 ms 24520 KB Output is correct
3 Correct 31 ms 24520 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 61 ms 25084 KB Output is correct
2 Correct 63 ms 25760 KB Output is correct
3 Correct 40 ms 25760 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 283 ms 27540 KB Output is correct
2 Correct 235 ms 28844 KB Output is correct
3 Correct 93 ms 28844 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 749 ms 31044 KB Output is correct
2 Correct 841 ms 34368 KB Output is correct
3 Correct 352 ms 34368 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1417 ms 34368 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1155 ms 34368 KB Output is correct
2 Correct 821 ms 38172 KB Output is correct
3 Correct 470 ms 38172 KB Output is correct