oj.uz

Submission #984546

# Submission time Handle Problem Language Result Execution time Memory
984546 2024-05-16T18:34:11 Z Ahmed57 Alternating Current (BOI18_alternating) C++17
19 / 100
 3000 ms 11276 KB 
#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;
    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==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 = (max(n,m)<=1000?0:lol);i<(max(n,m)<=1000?m:lol+1);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";
}

Subtask #1
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 344 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Execution timed out 3084 ms 348 KB Time limit exceeded
5 Halted 0 ms 0 KB -

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 344 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Execution timed out 3084 ms 348 KB Time limit exceeded
5 Halted 0 ms 0 KB -

Subtask #3
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 344 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Execution timed out 3084 ms 348 KB Time limit exceeded
5 Halted 0 ms 0 KB -

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 9956 KB Output is correct
2 Correct 3 ms 4188 KB Output is correct
3 Correct 11 ms 6672 KB Output is correct
4 Correct 15 ms 7440 KB Output is correct
5 Correct 26 ms 9992 KB Output is correct
6 Correct 23 ms 9232 KB Output is correct
7 Correct 25 ms 9740 KB Output is correct
8 Correct 4 ms 4444 KB Output is correct
9 Correct 4 ms 4188 KB Output is correct
10 Correct 36 ms 10124 KB Output is correct
11 Correct 22 ms 10252 KB Output is correct
12 Correct 24 ms 10764 KB Output is correct
13 Correct 2 ms 3420 KB Output is correct
14 Correct 3 ms 3532 KB Output is correct
15 Correct 34 ms 11200 KB Output is correct
16 Correct 11 ms 7184 KB Output is correct
17 Correct 28 ms 11276 KB Output is correct
18 Correct 20 ms 7952 KB Output is correct
19 Correct 4 ms 3932 KB Output is correct
20 Correct 23 ms 8972 KB Output is correct

Subtask #5
0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 344 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Execution timed out 3084 ms 348 KB Time limit exceeded
5 Halted 0 ms 0 KB -