Submission #1040468

#	Time	Username	Problem	Language	Result	Execution time	Memory
1040468		boyliguanhan	Toy Train (IOI17_train)	C++17	100 / 100	1130 ms	3944 KiB

train

#include "train.h"
#include<bits/stdc++.h>
using namespace std;
set<int>radj[5010],adj[5010];
set<int>inv(vector<int>v,set<int>st){
    for(auto i:v)
        st.erase(i);
    return st;
}
vector<int>aset(set<int>v,vector<int>own){
    vector<int>cnt(5000),don(5000);
    queue<int>q;
    vector<int>ans;
    for(auto i:v)
        q.push(i),don[i]=1;
    while(q.size()){
        int x=q.front(); q.pop();
        ans.push_back(x);
        for(auto i:radj[x]) {
            if(don[i])continue;
            if(own[i]) q.push(i),don[i]=1;
            else if(++cnt[i]==adj[i].size())
                q.push(i),don[i]=1;
        }
    }
    return ans;
}
std::vector<int> who_wins(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v) {
    int N=a.size(),M=u.size();
	std::vector<int> res(a.size()),bozo=a;
    for(auto&i:bozo)i=!i;
    for(int i=0;i<M;i++)
        adj[u[i]].insert(v[i]),
        radj[v[i]].insert(u[i]);
    set<int>charg,hav;
    for(int i=0;i<N;hav.insert(i++))
        if(r[i])charg.insert(i);
    int CC=N;
    while(CC) {
        vector<int>v=aset(charg,a);
        if(v.size()==CC){
            for(auto i:v)
                res[i]=1;
            break;
        }
        v=aset(inv(v,hav),bozo);
        for(auto i:v){ CC--;
            charg.erase(i);
            hav.erase(i);
            for(auto j:adj[i])
                radj[j].erase(i);
            for(auto j:radj[i])
                adj[j].erase(i);
            adj[i].clear();
            radj[i].clear();
        }
    }
	return res;
}

Compilation message (stderr)

train.cpp: In function 'std::vector<int> aset(std::set<int>, std::vector<int>)':
train.cpp:22:29: warning: comparison of integer expressions of different signedness: '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} and 'std::set<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |             else if(++cnt[i]==adj[i].size())
      |                     ~~~~~~~~^~~~~~~~~~~~~~~
train.cpp: In function 'std::vector<int> who_wins(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:41:20: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   41 |         if(v.size()==CC){
      |            ~~~~~~~~^~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 11 / 11
• Subtask 4: 11 / 11
• Subtask 5: 12 / 12
• Subtask 6: 51 / 51