Submission #342405

#	Time	Username	Problem	Language	Result	Execution time	Memory
342405		mjhmjh1104	Spring cleaning (CEOI20_cleaning)	C++14	9 / 100	53 ms	7908 KiB

cleaning

#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;

const int MAX = 100006;

int n, q, d, childs[MAX];
vector<int> adj[MAX];

int main() {
    scanf("%d%d", &n, &q);
    for (int i = 0; i < n - 1; i++) {
        int a, b;
        scanf("%d%d", &a, &b);
        a--, b--;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    scanf("%d", &d);
    for (int i = 0; i < d; i++) {
        int x;
        scanf("%d", &x); x--;
        childs[x]++;
    }
    int cnt = 0;
    for (int i = 1; i < n; i++) cnt += max(childs[i], 1);
    if (cnt % 2) return puts("-1"), 0;
    long long res = 0;
    for (int i = 1; i < n; i++) if (childs[i] > 2) res += (childs[i] - 1) / 2 * 2, childs[i] -= (childs[i] - 1) / 2 * 2;
    for (int i = 1; i < n; i++) if (childs[i]) res += childs[i] * 2; else res++;
    printf("%lld", res);
}

Compilation message (stderr)

cleaning.cpp: In function 'int main()':
cleaning.cpp:12:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   12 |     scanf("%d%d", &n, &q);
      |     ~~~~~^~~~~~~~~~~~~~~~
cleaning.cpp:15:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   15 |         scanf("%d%d", &a, &b);
      |         ~~~~~^~~~~~~~~~~~~~~~
cleaning.cpp:20:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   20 |     scanf("%d", &d);
      |     ~~~~~^~~~~~~~~~
cleaning.cpp:23:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   23 |         scanf("%d", &x); x--;
      |         ~~~~~^~~~~~~~~~

• Subtask 1: 0 / 0
• Subtask 2: 9 / 9
• Subtask 3: 0 / 9
• Subtask 4: 0 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 17
• Subtask 7: 0 / 30