#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(long long i=0;i<(long long)(n);i++)
#define REP(i,k,n) for(long long i=k;i<(long long)(n);i++)
#define pb emplace_back
#define lb(v,k) (lower_bound(all(v),(k))-v.begin())
#define ub(v,k) (upper_bound(all(v),(k))-v.begin())
#define fi first
#define se second
#define pi M_PI
#define PQ(T) priority_queue<T>
#define SPQ(T) priority_queue<T,vector<T>,greater<T>>
#define dame(a) {out(a);return 0;}
#define decimal cout<<fixed<<setprecision(15);
#define all(a) a.begin(),a.end()
#define rsort(a) {sort(all(a));reverse(all(a));}
#define dupli(a) {sort(all(a));a.erase(unique(all(a)),a.end());}
typedef long long ll;
typedef pair<ll,ll> P;
typedef tuple<ll,ll,ll> PP;
typedef tuple<ll,ll,ll,ll> PPP;
using vi=vector<ll>;
using vvi=vector<vi>;
using vvvi=vector<vvi>;
using vvvvi=vector<vvvi>;
using vp=vector<P>;
using vvp=vector<vp>;
using vb=vector<bool>;
using vvb=vector<vb>;
const ll inf=1001001001001001001;
const ll INF=1001001001;
const ll mod=1000000007;
const double eps=1e-10;
template<class T> bool chmin(T&a,T b){if(a>b){a=b;return true;}return false;}
template<class T> bool chmax(T&a,T b){if(a<b){a=b;return true;}return false;}
template<class T> void out(T a){cout<<a<<'\n';}
template<class T> void outp(T a){cout<<'('<<a.fi<<','<<a.se<<')'<<'\n';}
template<class T> void outvp(T v){rep(i,v.size())cout<<'('<<v[i].fi<<','<<v[i].se<<')';cout<<'\n';}
template<class T> void outvvp(T v){rep(i,v.size())outvp(v[i]);}
template<class T> void outv(T v){rep(i,v.size()){if(i)cout<<' ';cout<<v[i];}cout<<'\n';}
template<class T> void outvv(T v){rep(i,v.size())outv(v[i]);}
template<class T> bool isin(T x,T l,T r){return (l)<=(x)&&(x)<=(r);}
template<class T> void yesno(T b){if(b)out("yes");else out("no");}
template<class T> void YesNo(T b){if(b)out("Yes");else out("No");}
template<class T> void YESNO(T b){if(b)out("YES");else out("NO");}
template<class T> void outset(T s){auto itr=s.begin();while(itr!=s.end()){if(itr!=s.begin())cout<<' ';cout<<*itr;itr++;}cout<<'\n';}
void outs(ll a,ll b){if(a>=inf-100)out(b);else out(a);}
ll gcd(ll a,ll b){if(b==0)return a;return gcd(b,a%b);}
ll modpow(ll a,ll b){ll res=1;a%=mod;while(b){if(b&1)res=res*a%mod;a=a*a%mod;b>>=1;}return res;}
int main(){
ll n,m;cin>>n>>m;
vp v(m),srt(m);
vi cnt(n);
rep(i,m){
ll a,b;cin>>a>>b;a--;b--;
assert(a<=b);
v[i]=P(a,b);
srt[i]=P(a,i);
cnt[a]++;if(b!=n-1)cnt[b+1]--;
}rep(i,n-1)cnt[i+1]+=cnt[i];rep(i,n)if(cnt[i]<2)dame("impossible");
sort(all(srt));
P ma=P(-1,-1);
vvi g(m);
vi rui(n);vp tmp;
rep(i,m){
ll id=srt[i].se;
if(ma.fi<v[id].se){
chmax(ma,P(v[id].se,id));
tmp.pb(srt[i]);
}
else{
g[ma.se].pb(id);
rui[v[id].fi]++;if(v[id].se!=n-1)rui[v[id].se+1]--;
}
}
rep(i,n-1)rui[i+1]+=rui[i];
vi ans(m);
queue<ll> que;
rep(i,tmp.size()){
ans[tmp[i].se]=i%2;
for(ll x:g[tmp[i].se]){
ans[x]=1-ans[tmp[i].se];
que.push(x);
}
}
while(!que.empty()){
ll t=que.front();que.pop();
for(ll x:g[t]){
ans[x]=1-ans[t];que.push(x);
}
}
rep(i,m)cout<<ans[i];cout<<endl;
}
Compilation message
alternating.cpp: In function 'int main()':
alternating.cpp:3:20: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
3 | #define rep(i, n) for(long long i=0;i<(long long)(n);i++)
| ^~~
alternating.cpp:93:5: note: in expansion of macro 'rep'
93 | rep(i,m)cout<<ans[i];cout<<endl;
| ^~~
alternating.cpp:93:26: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
93 | rep(i,m)cout<<ans[i];cout<<endl;
| ^~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
204 KB |
Output is correct |
| 2 |
Correct |
1 ms |
204 KB |
Output is correct |
| 3 |
Runtime error |
1 ms |
332 KB |
Execution killed with signal 6 |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
204 KB |
Output is correct |
| 2 |
Correct |
1 ms |
204 KB |
Output is correct |
| 3 |
Runtime error |
1 ms |
332 KB |
Execution killed with signal 6 |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
204 KB |
Output is correct |
| 2 |
Correct |
1 ms |
204 KB |
Output is correct |
| 3 |
Runtime error |
1 ms |
332 KB |
Execution killed with signal 6 |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
82 ms |
10704 KB |
Output is correct |
| 2 |
Correct |
2 ms |
1868 KB |
Output is correct |
| 3 |
Correct |
39 ms |
3216 KB |
Output is correct |
| 4 |
Correct |
46 ms |
6416 KB |
Output is correct |
| 5 |
Correct |
92 ms |
11192 KB |
Output is correct |
| 6 |
Correct |
69 ms |
5340 KB |
Output is correct |
| 7 |
Correct |
82 ms |
10396 KB |
Output is correct |
| 8 |
Correct |
4 ms |
2124 KB |
Output is correct |
| 9 |
Correct |
2 ms |
1868 KB |
Output is correct |
| 10 |
Correct |
94 ms |
11600 KB |
Output is correct |
| 11 |
Correct |
72 ms |
8964 KB |
Output is correct |
| 12 |
Correct |
88 ms |
9996 KB |
Output is correct |
| 13 |
Correct |
2 ms |
1152 KB |
Output is correct |
| 14 |
Correct |
2 ms |
976 KB |
Output is correct |
| 15 |
Correct |
95 ms |
10940 KB |
Output is correct |
| 16 |
Correct |
33 ms |
3148 KB |
Output is correct |
| 17 |
Correct |
90 ms |
10980 KB |
Output is correct |
| 18 |
Correct |
87 ms |
9276 KB |
Output is correct |
| 19 |
Correct |
5 ms |
1228 KB |
Output is correct |
| 20 |
Correct |
92 ms |
11332 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
204 KB |
Output is correct |
| 2 |
Correct |
1 ms |
204 KB |
Output is correct |
| 3 |
Runtime error |
1 ms |
332 KB |
Execution killed with signal 6 |
| 4 |
Halted |
0 ms |
0 KB |
- |
