Submission #473614

#	Time	Username	Problem	Language	Result	Execution time	Memory
473614		Blobo2_Blobo2	Alternating Current (BOI18_alternating)	C++14	13 / 100	3069 ms	1048580 KiB

alternating

/*
Editor: Abdelrahman Hossam
Nickname: Blobo2_Blobo2
IOI next year isA :)
*/
/*#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,sse4.2,popcnt,abm,mmx,avx2,tune=native")
#pragma GCC optimize("-ffast-math")
#pragma GCC optimize("-funroll-loops")
#pragma GCC optimize("-funroll-all-loops,-fpeel-loops,-funswitch-loops")*/

#include<bits/stdc++.h>
using namespace std;
//#define int long long
#define endl "\n"
#define all(v)  v.begin(),v.end()
#define gen(arr,n,nxt)  generate(arr,arr+n,nxt)
#define Blobo2_el_7akim_elly_3ayz_yro7_IOI_w_3ayz_yakol_jilaty ios_base::sync_with_stdio(false);cin.tie(0);
#define EPS 0.00000001

const int mo=1e9+7,INF=1e18;
int nxt(){int x;cin>>x;return x;}
vector<pair<int,int> >v;
int n,m;
void solve(int idx = 0,string ans = ""){
    if(idx == v.size()){
        int vis[n+1];
        memset(vis,0,sizeof vis);
        for(int i=0;i<v.size();i++){

            if(ans[i] == '0'){
                if(v[i].first>v[i].second){
                    for(int j = v[i].first;j<=n;j++)
                        vis[j] = (vis[j] == 2 || vis[j] == 3?3:1);
                    for(int j = 1;j<=v[i].second;j++)
                        vis[j] = (vis[j] == 2 || vis[j] == 3?3:1);
                }
                else{
                    for(int j=v[i].first;j<=v[i].second;j++)
                        vis[j] = (vis[j] == 2 || vis[j] == 3?3:1);
                }
            }
            else{
                if(v[i].first>v[i].second){
                    for(int j = v[i].first;j<=n;j++)
                        vis[j] = (vis[j] == 1 || vis[j] == 3?3:2);
                    for(int j = 1;j<=v[i].second;j++)
                        vis[j] = (vis[j] == 1 || vis[j] == 3?3:2);
                }
                else{
                    for(int j=v[i].first;j<=v[i].second;j++)
                        vis[j] = (vis[j] == 1 || vis[j] == 3?3:2);
                }
            }
        }
        bool ok=1;
        for(int i=1;i<=n;i++){
            ok &= (vis[i] == 3);
        }
        if(ok){
            cout<<ans<<endl;
            exit(0);
        }
        return;
    }
    solve(idx+1,ans+'0');
    solve(idx+1,ans+'1');
}
signed main(){
    Blobo2_el_7akim_elly_3ayz_yro7_IOI_w_3ayz_yakol_jilaty
    n=nxt(),m=nxt();
    for(int i=0;i<m;i++)
        v.push_back({nxt(),nxt()});
    solve();
    cout<<"impossible";
    return 0;
}

Compilation message (stderr)

alternating.cpp:21:24: warning: overflow in conversion from 'double' to 'int' changes value from '1.0e+18' to '2147483647' [-Woverflow]
   21 | const int mo=1e9+7,INF=1e18;
      |                        ^~~~
alternating.cpp: In function 'void solve(int, std::string)':
alternating.cpp:26:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |     if(idx == v.size()){
      |        ~~~~^~~~~~~~~~~
alternating.cpp:29:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |         for(int i=0;i<v.size();i++){
      |                     ~^~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 0 / 20
• Subtask 3: 0 / 22
• Subtask 4: 0 / 19
• Subtask 5: 0 / 26