Submission #321197

#	Time	Username	Problem	Language	Result	Execution time	Memory
321197		urd05	Friend (IOI14_friend)	C++14	100 / 100	56 ms	8928 KiB

friend

#include <bits/stdc++.h>
using namespace std;
 
int n;
int co[100000];
int ho[100000];
int pro[100000];
typedef pair<int,int> P;
vector<P> son[100000];
int dp[100000][2];
int temp[100000];

int ans(int v,int type) {
    if (dp[v][type]!=-1) {
        return dp[v][type];
    }
    if (type==0) {
        int ret=0;
        int sum=0;
        for(int i=0;i<son[v].size();i++) {
            if (son[v][i].second==0)
                sum+=ans(son[v][i].first,1);
            else
                sum+=ans(son[v][i].first,0);
        }
        ret=sum;
        dp[v][type]=ret;
        return ret;
    }
    int ret=0;
    int sum=0;
    for(int i=0;i<son[v].size();i++) {
        if (son[v][i].second==0)
            sum+=ans(son[v][i].first,1);
        else
            sum+=ans(son[v][i].first,0);
    }
    ret=sum;
    for(int i=0;i<son[v].size();i++) {
        int nt=son[v][i].first;
        if (son[v][i].second==2) {
            ret=max(ret,sum+ans(nt,1)-ans(nt,0));
        }
        if (son[v][i].second==0) {
            sum-=ans(nt,1)-ans(nt,0);
        }
        if (son[v][i].second==1) {
            sum+=ans(nt,1)-ans(nt,0);
        }
        ret=max(ret,sum);
    }
    ret=max(ret,sum+co[v]);
    dp[v][type]=ret;
    return ret;
}
 
int findSample(int nn,int conf[],int hos[],int prot[]) {
    memset(dp,-1,sizeof(dp));
    n=nn;
    for(int i=0;i<n;i++) {
        co[i]=conf[i];
        ho[i]=hos[i];
        pro[i]=prot[i];
    }
    for(int i=1;i<n;i++) {
        son[ho[i]].push_back(P(i,pro[i]));
    }
    return ans(0,1);
}

Compilation message (stderr)

friend.cpp: In function 'int ans(int, int)':
friend.cpp:20:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |         for(int i=0;i<son[v].size();i++) {
      |                     ~^~~~~~~~~~~~~~
friend.cpp:32:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |     for(int i=0;i<son[v].size();i++) {
      |                 ~^~~~~~~~~~~~~~
friend.cpp:39:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |     for(int i=0;i<son[v].size();i++) {
      |                 ~^~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 8 / 8
• Subtask 3: 8 / 8
• Subtask 4: 19 / 19
• Subtask 5: 23 / 23
• Subtask 6: 31 / 31