Submission #227966

#	Time	Username	Problem	Language	Result	Execution time	Memory
227966		urd05	Friend (IOI14_friend)	C++14	30 / 100	45 ms	5240 KiB

friend

#include <bits/stdc++.h>
using namespace std;
 
int n;
int co[100000];
int ho[100000];
int pro[100000];
int con[10][10];
vector<int> son[1000];
int dp[1000][2];

int ans(int now,int stat) {
    if (dp[now][stat]!=-1) {
        return dp[now][stat];
    }
    int ret=0;
    if (stat==1) {
        ret+=co[now];
    }
    if (stat==0) {
        for(int i=0;i<son[now].size();i++) {
            ret+=max(ans(son[now][i],0),ans(son[now][i],1));
        }
    }
    else {
        for(int i=0;i<son[now].size();i++) {
            ret+=ans(son[now][i],0);
        }
    }
    dp[now][stat]=ret;
    return ret;
}
 
int findSample(int nn,int conf[],int hos[],int prot[]) {
    n=nn;
    for(int i=0;i<n;i++) {
        co[i]=conf[i];
        ho[i]=hos[i];
        pro[i]=prot[i];
    }
    if (n<=10) {
        for(int i=1;i<n;i++) {
            if (pro[i]==0) {
                con[ho[i]][i]=1;
                con[i][ho[i]]=1;
            }
            if (pro[i]==1) {
                for(int j=0;j<n;j++) {
                    if (con[ho[i]][j]==1) {
                        con[i][j]=1;
                        con[j][i]=1;
                    }
                }
            }
            if (pro[i]==2) {
                for(int j=0;j<n;j++) {
                    if (con[ho[i]][j]==1) {
                        con[i][j]=1;
                        con[j][i]=1;
                    }
                }
                con[ho[i]][i]=1;
                con[i][ho[i]]=1;
            }
        }
        int ret=0;
        for(int i=0;i<(1<<n);i++) {
            bool use[10];
            memset(use,0,sizeof(use));
            for(int j=0;j<n;j++) {
                if ((i&(1<<j))!=0) {
                    use[j]=true;
                }
            }
            bool flag=true;
            for(int j=0;j<n;j++) {
                for(int k=0;k<n;k++) {
                    if (con[k][j]==1&&use[k]&&use[j]) {
                        flag=false;
                        break;
                    }
                }
            }
            if (!flag) {
                continue;
            }
            int val=0;
            for(int j=0;j<n;j++) {
                if (use[j]) {
                    val+=co[j];
                }
            }
            ret=max(ret,val);
        }
        return ret;
    }
    for(int i=1;i<n;i++) {
        son[ho[i]].push_back(i);
    }
    memset(dp,-1,sizeof(dp));
    return max(ans(0,0),ans(0,1));
}

Compilation message (stderr)

friend.cpp: In function 'int ans(int, int)':
friend.cpp:21:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=0;i<son[now].size();i++) {
                     ~^~~~~~~~~~~~~~~~
friend.cpp:26:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=0;i<son[now].size();i++) {
                     ~^~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 0 / 8
• Subtask 3: 0 / 8
• Subtask 4: 19 / 19
• Subtask 5: 0 / 23
• Subtask 6: 0 / 31