Submission #925388

#	Time	Username	Problem	Language	Result	Execution time	Memory
925388		ttamx	Cat in a tree (BOI17_catinatree)	C++14	0 / 100	73 ms	139900 KiB

catinatree

#include<bits/stdc++.h>

using namespace std;

const int N=2e5+5;

int n,d;
vector<int> adj[N];
deque<int> dp[N];

int get(int i,int j){
    return j<dp[i].size()?dp[i][j]:0;
}

void dfs(int u){
    dp[u].emplace_back(1);
    for(auto v:adj[u]){
        dfs(v);
        dp[v].emplace_front(0);
        if(dp[v].size()>dp[u].size())swap(dp[u],dp[v]);
        vector<int> res;
        for(int i=0;i<dp[v].size();i++){
            if(i>d-i)break;
            int du=dp[u][i]+get(v,d-i);
            int dv=dp[v][i]+get(u,d-i);
            res.emplace_back(max(du,dv));
        }
        for(int i=0;i<res.size();i++)dp[u][i]=res[i];
        for(int i=res.size()-2;i>=0;i--)dp[u][i]=max(dp[u][i],dp[u][i+1]);
        dp[v].clear();
    }
    if(dp[u].size()==d+1){
        dp[u][0]=max(dp[u][0],dp[u][d]+1);
        dp[u].pop_back();
    }
}

int main(){
    cin.tie(nullptr)->sync_with_stdio(false);
    cin >> n >> d;
    for(int i=1;i<n;i++){
        int p;
        cin >> p;
        adj[p].emplace_back(i);
    }
    dfs(0);
    cout << dp[0][0];
}

Compilation message (stderr)

catinatree.cpp: In function 'int get(int, int)':
catinatree.cpp:12:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |     return j<dp[i].size()?dp[i][j]:0;
      |            ~^~~~~~~~~~~~~
catinatree.cpp: In function 'void dfs(int)':
catinatree.cpp:22:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |         for(int i=0;i<dp[v].size();i++){
      |                     ~^~~~~~~~~~~~~
catinatree.cpp:28:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |         for(int i=0;i<res.size();i++)dp[u][i]=res[i];
      |                     ~^~~~~~~~~~~
catinatree.cpp:32:20: warning: comparison of integer expressions of different signedness: 'std::deque<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   32 |     if(dp[u].size()==d+1){
      |        ~~~~~~~~~~~~^~~~~

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