Submission #809066

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Source Code Expand

#include<bits/stdc++.h>
#define CLR(a,b) memset(a,b,sizeof(a))
#define LL long long

using namespace std;

vector<LL>graph[3005];
vector<LL>cost[3005];
bool visited[3005];
LL dis[3005];

void BFS(LL x, LL &y)
{
    CLR(visited,false);
    CLR(dis,0);
    queue<LL>q;

    q.push(x);
    visited[x]=true;
    dis[x]=0;
    LL maxi = -1;
    while(!q.empty())
    {
        LL u = q.front();
        q.pop();
        for(LL i=0; i<graph[u].size(); i++)
        {
            LL v = graph[u][i];
            LL c = cost[u][i];
            if(!visited[v])
            {
                visited[v]=true;
                dis[v] = dis[u]+cost[u][i];
                if(dis[v]>maxi)
                {
                    maxi=dis[v];
                    y = v;
                }
                q.push(v);
            }
        }
    }

}

void BFS2(LL x)
{
    memset(dis, 0, sizeof dis);
    memset(visited, 0, sizeof visited);

    queue<LL>q;
    q.push(x);
    visited[x] = true;
    dis[x] = 0;
    while(!q.empty())
    {
        LL u = q.front();
        q.pop();
        for(LL i=0; i<graph[u].size(); i++)
        {
            LL v = graph[u][i];
            if(!visited[v])
            {
                visited[v] = true;
                dis[v] = dis[u] + cost[u][i];
                q.push(v);
            }
        }
    }
}

int main()
{
    LL test, K;
    LL nodes;
    scanf("%lld %lld", &nodes, &K);
    for(LL i=1; i<nodes; i++)
    {
        LL x, y;
        scanf("%lld %lld", &x, &y);
        graph[x].push_back(y);
        graph[y].push_back(x);
        cost[x].push_back(1);
        cost[y].push_back(1);
    }
    LL s, t, w;
    BFS(1,s);
    BFS(s,t);
  //  cout<<"S = "<<t<<endl;
    BFS2(t);
  //  cout<<s<<' '<<t<<' '<<w<<endl;

    LL cnt1 = 0, cnt2 = 0;
    for(LL i=1; i<=nodes; i++)
    {
       // cout<<dis[i]<<endl;
        if(dis[i]>K) cnt1++;
    }
    // cout<<"S = "<<s<<endl;
    BFS2(s);
  //  cout<<s<<' '<<t<<' '<<w<<endl;

    cnt2 = 0;
    for(LL i=1; i<=nodes; i++)
    {
       // cout<<dis[i]<<endl;
        if(dis[i]>K) cnt2++;
    }

    printf("%lld", min(cnt1, cnt2));
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:76:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%lld %lld", &nodes, &K);
                                   ^
./Main.cpp:80:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld %lld", &x, &y);
                                   ^

Judge Result