#include <bits/stdc++.h>
using namespace std;
#define int long long
signed main(){
ios_base::sync_with_stdio(false);cin.tie(0);
int n,m;cin>>n>>m;
int pref[n+2] = {0};
vector<array<int,3>> v;
vector<array<int,2>> rng[n+1];
int dir[m+1] = {0};
int ma = -1, lol = -1;
int mi = 1e9;
for(int i = 0;i<m;i++){
int a,b;cin>>a>>b;
if(a<=b){
pref[a]++;
pref[b+1]--;
}else{
pref[a]++;
pref[1]++;
pref[b+1]--;
b+=n;
}
v.push_back({a,b,i});
rng[a].push_back({b,i});
if(a<=mi){
if(a<mi){
mi = a;
ma = -1;
}
if(b>ma){
ma = b;
lol = i;
}
}
}
for(int i = 2;i<=n;i++){
pref[i]+=pref[i-1];
}
for(int i = 1;i<=n;i++){
if(pref[i]<=1){
cout<<"impossible\n";
return 0;
}
}
for(int i = lol;i>=lol;i--){
for(int j = 0;j<m;j++)dir[j] = 0;
int ind = v[i][0];
int nah = v[i][1], fe = v[i][2];
bool bad = 0;
while(ind<v[i][0]+n){
if(ind-1==nah){
bad = 1;
break;
}
if(nah==-1){
bad = 1;
break;
}
int er = nah;
dir[fe] = 1;
if(er>=v[i][0]+n){
break;
}
while(ind<=er){
ind++;
for(auto j:rng[(ind-1)%n+1]){
if(nah<(j[0]>n?j[0]:(ind<=n?j[0]:j[0]+n))){
nah = (j[0]>n?j[0]:(ind<=n?j[0]:j[0]+n));
fe = j[1];
}
}
if(ind<=er&&pref[(ind-1)%n+1]==2)nah = -1;
}
}
int npref[n+2];
for(int j = 1;j<=n;j++){
npref[j] = 0;
}
for(int j = 0;j<m;j++){
if(dir[j])continue;
if(v[j][1]>n){
npref[v[j][0]]++;
npref[1]++;
npref[(v[j][1]-1)%n+2]--;
}else{
npref[v[j][0]]++;
npref[v[j][1]+1]--;
}
}
for(int j = 2;j<=n;j++)npref[j]+=npref[j-1];
for(int j = 1;j<=n;j++){
if(npref[j]==0){
bad = 1;
break;
}
}
if(bad==0){
for(int j = 0;j<m;j++){
cout<<dir[j];
}
return 0;
}
}
cout<<"impossible\n";
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Incorrect |
1 ms |
348 KB |
'impossible' claimed, but there is a solution |
6 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Incorrect |
1 ms |
348 KB |
'impossible' claimed, but there is a solution |
6 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Incorrect |
1 ms |
348 KB |
'impossible' claimed, but there is a solution |
6 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
21 ms |
9444 KB |
Output is correct |
2 |
Correct |
3 ms |
4184 KB |
Output is correct |
3 |
Correct |
10 ms |
6672 KB |
Output is correct |
4 |
Correct |
13 ms |
7440 KB |
Output is correct |
5 |
Correct |
34 ms |
10256 KB |
Output is correct |
6 |
Correct |
23 ms |
9452 KB |
Output is correct |
7 |
Correct |
25 ms |
10256 KB |
Output is correct |
8 |
Correct |
4 ms |
4444 KB |
Output is correct |
9 |
Correct |
3 ms |
4188 KB |
Output is correct |
10 |
Correct |
29 ms |
10504 KB |
Output is correct |
11 |
Correct |
22 ms |
8972 KB |
Output is correct |
12 |
Correct |
23 ms |
10512 KB |
Output is correct |
13 |
Correct |
2 ms |
3416 KB |
Output is correct |
14 |
Correct |
2 ms |
3420 KB |
Output is correct |
15 |
Correct |
27 ms |
10244 KB |
Output is correct |
16 |
Correct |
11 ms |
6672 KB |
Output is correct |
17 |
Correct |
28 ms |
10056 KB |
Output is correct |
18 |
Correct |
19 ms |
7572 KB |
Output is correct |
19 |
Correct |
4 ms |
3932 KB |
Output is correct |
20 |
Correct |
23 ms |
7776 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Incorrect |
1 ms |
348 KB |
'impossible' claimed, but there is a solution |
6 |
Halted |
0 ms |
0 KB |
- |