Submission #44631

#	Time	Username	Problem	Language	Result	Execution time	Memory
44631		RayaBurong25_1	Network (BOI15_net)	C++17	0 / 100	14 ms	12132 KiB

net

#include <stdio.h>
#include <vector>
std::vector<int> AdjList[500005];
std::vector<int> Leaf;
int Root;
void dfs(int u, int pa)
{
    if (pa == 0)
        Root = u;
    int i, v, s = AdjList[u].size();
    for (i = 0; i < s; i++)
    {
        v = AdjList[u][i];
        if (v != pa)
        {
            dfs(v, u);
        }
    }
    if (s == 1)
        Leaf.push_back(u);
}
int main()
{
    int N;
    scanf("%d", &N);
    int i, j, u, v;
    for (i = 0; i < N - 1; i++)
    {
        scanf("%d %d", &u, &v);
        AdjList[u].push_back(v);
        AdjList[v].push_back(u);
    }
    if (AdjList[1].size() > 1)
        dfs(1, 0);
    else
        dfs(AdjList[1][0], 0);
    printf("%d\n", (Leaf.size() + 1)/2);
    for (i = 0, j = Leaf.size() - 1; i < j; i++, j--)
        printf("%d %d\n", Leaf[i], Leaf[j]);
    if (i == j)
        printf("%d %d\n", Leaf[i], Root);
}

Compilation message (stderr)

net.cpp: In function 'int main()':
net.cpp:37:39: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<int>::size_type {aka long unsigned int}' [-Wformat=]
     printf("%d\n", (Leaf.size() + 1)/2);
                    ~~~~~~~~~~~~~~~~~~~^
net.cpp:25:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &N);
     ~~~~~^~~~~~~~~~
net.cpp:29:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &u, &v);
         ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 18
• Subtask 2: 0 / 45
• Subtask 3: 0 / 37