Submission #129643

#	Time	Username	Problem	Language	Result	Execution time	Memory
129643		Vardanyan	Cat in a tree (BOI17_catinatree)	C++14	51 / 100	1071 ms	14444 KiB

catinatree

#include <bits/stdc++.h>
using namespace std;
const int N = 2*1000*100+5;
vector<int> g[N];
int mark[N];
int depth[N];
int par[N];
void dfs(int v,int p = -1){
   if(p!=-1) depth[v] = depth[p]+1;
   par[v] = p;
    for(int i = 0;i<g[v].size();i++){
        int to = g[v][i];
        if(to == p) continue;
        dfs(to,v);
    }

}
bool cmp(int a,int b){
    return depth[a]>depth[b];
}
bool col[N];
int d;
int mr = 0;
int nw;
void go(int v,int dd = 0,int p = -1){
    if(dd>=d) return;
    mark[v] = 1;
    mr++;
    for(int i = 0;i<g[v].size();i++){
        int to = g[v][i];
        if(to == p || to == nw) continue;
        go(to,dd+1,v);
    }
}
int main(){
    ios_base::sync_with_stdio(false);
    int n;
    cin>>n>>d;
    for(int i = 1;i<=n-1;i++){
        int x;
        cin>>x;
        g[i].push_back(x);
        g[x].push_back(i);
    }
    dfs(0);
    vector<int> v;
    for(int i = 0;i<n;i++) v.push_back(i);
    sort(v.begin(),v.end(),cmp);
    int ans = 0;
    int num = 1;
    for(int jj = 0;jj<n;jj++){
        int i = v[jj];
        if(mark[i]) continue;
        mark[i] = 1;
        ans++;
        nw = i;
        go(par[i],1);
    //    if(mr == n) break;
        /*queue<pair<int,int> > q;
        q.push({i,0});
        num++;
        col[i] = num;
        while(!q.empty()){
            pair<int,int> x = q.front();
            int gag = x.first;
            int dd = x.second;
            q.pop();
            if(dd>=d) continue;
            mark[gag] = 1;

            for(int j = 0;j<g[gag].size();j++){
                int to = g[gag][j];
                if(col[to]!=num){
                    q.push({to,dd+1});
                    col[to] = num;
                }
            }
        }*/
 //       for(int i = 0;i<n;i++) cout<<mark[i]<<" ";
 //       cout<<endl;
    }
    cout<<max(1,ans)<<endl;
    return 0;
}

Compilation message (stderr)

catinatree.cpp: In function 'void dfs(int, int)':
catinatree.cpp:11:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0;i<g[v].size();i++){
                   ~^~~~~~~~~~~~
catinatree.cpp: In function 'void go(int, int, int)':
catinatree.cpp:29:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0;i<g[v].size();i++){
                   ~^~~~~~~~~~~~
catinatree.cpp: In function 'int main()':
catinatree.cpp:50:9: warning: unused variable 'num' [-Wunused-variable]
     int num = 1;
         ^~~

• Subtask 1: 11 / 11
• Subtask 2: 40 / 40
• Subtask 3: 0 / 49