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Submission #173673

# Submission time Handle Problem Language Result Execution time Memory
173673 2020-01-04T23:21:54 Z rzbt One-Way Streets (CEOI17_oneway) C++14
100 / 100
 217 ms 28864 KB 
#include <bits/stdc++.h>
#define mp make_pair
#define pb push_back
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define MAXN 100005
typedef long long ll;


using namespace std;

vector<pair<int,int> > niz[MAXN];
vector<pair<int,int> > stablo[MAXN];
int n,m,p;
bool most[MAXN],obidjen[MAXN];
int ulaz[MAXN],dub[MAXN];
int predak[MAXN][21];
int grupa[MAXN];
int vreme;
int dokle[MAXN],smer[MAXN];
int leva[MAXN];
char s[MAXN];
int dfsM(int t,int o){
    vreme++;
    ulaz[t]=vreme;
    obidjen[t]=true;
    int minv=vreme;
    for(auto x:niz[t]){

        if(x.S==o)continue;
        int tv;

        if(obidjen[x.F])tv=ulaz[x.F];
        else tv=dfsM(x.F,x.S);

        if(tv>ulaz[t])most[x.S]=true;
        minv=min(minv,tv);
    }
    return minv;

}

void dfsS(int t,int kad,int h){
    //printf("   %d    %d     grupa\n",t,kad);
    grupa[t]=kad;
    obidjen[t]=true;
    dub[kad]=h;
    for(auto x:niz[t]){
        if(obidjen[x.F])continue;
        if(most[x.S]){
            vreme++;
            stablo[kad].pb(mp(vreme,x.S));
            predak[vreme][0]=kad;
            dfsS(x.F,vreme,h+1);
        }
        else dfsS(x.F,kad,h);

    }
}


int lca(int a,int b){
    if(dub[b]>dub[a])swap(a,b);
    for(int j=20;j>=0;j--)
        if(dub[predak[a][j]]>=dub[b])
            a=predak[a][j];
    if(a==b)return a;
    for(int j=20;j>=0;j--){
        if(predak[a][j]!=predak[b][j]){
            a=predak[a][j];
            b=predak[b][j];
        }
    }
    return predak[a][0];
}

void dfs(int t,int o,int caleg){
    //printf("%d %d\n",t,caleg);
    obidjen[t]=true;
    for(auto x:stablo[t]){
        if(x.F==o)continue;
        dfs(x.F,t,x.S);
    }
    if(o==0 || dokle[t]==0 || dokle[t]==t)return;
    if(smer[t]==1){
        //printf("  1 %d %d %d\n",caleg,t,leva[caleg]);
        if(t==leva[caleg])s[caleg-1]='L';
        else s[caleg-1]='R';
    }else if (smer[t]==-1){
        //printf(" -1 %d %d %d\n",caleg,t,leva[caleg]);
        if(t==leva[caleg])s[caleg-1]='R';
        else s[caleg-1]='L';
    }
    if(dokle[t]==o)return;

    if(dokle[o]==0 || dokle[o]>dokle[t])dokle[o]=dokle[t];
    smer[o]=smer[t];
}


int main()///NE MORA DA VUDE POVEZAN
{
    //freopen("output.txt","w",stdout);
    scanf("%d %d", &n, &m);
    for(int i=1;i<=m;i++){
        int t1,t2;
        scanf("%d %d", &t1, &t2);
        niz[t1].pb(mp(t2,i));
        niz[t2].pb(mp(t1,i));
        //printf("       %d %d\n",i,t1);
        leva[i]=t1;
    }
    for(int i=1;i<=n;i++)
        if(!obidjen[i])dfsM(i,0);
    vreme=0;
    memset(obidjen,0,sizeof(obidjen));
    for(int i=1;i<=n;i++){
        if(!obidjen[i]){
            vreme++;
            dfsS(i,vreme,1);
        }
    }
    for(int j=1;j<21;j++){
        for(int i=1;i<=vreme;i++){
            predak[i][j]=predak[predak[i][j-1]][j-1];
        }
    }
    scanf("%d", &p);
    while(p--){
        int a,b;
        scanf("%d %d", &a, &b);
        a=grupa[a];
        b=grupa[b];
        int najnizi=lca(a,b);

        if(a!=najnizi)dokle[a]=najnizi;
        if(b!=najnizi)dokle[b]=najnizi;
        if(a!=najnizi)smer[a]=-1;
        if(b!=najnizi)smer[b]=1;
    }
    memset(obidjen,0,sizeof(obidjen));
    for(int i=0;i<m;i++)s[i]='B';
    s[m]=0;
    for(int i=1;i<=m;i++)leva[i]=grupa[leva[i]];
    for(int i=1;i<=n;i++)
        if(!obidjen[i])
            dfs(i,0,0);
    printf("%s",s);
    //printf("   %d\n",most[12]);
    return 0;
}

Compilation message

oneway.cpp: In function 'int main()':
oneway.cpp:105:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~~
oneway.cpp:108:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &t1, &t2);
         ~~~~~^~~~~~~~~~~~~~~~~~~
oneway.cpp:129:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &p);
     ~~~~~^~~~~~~~~~
oneway.cpp:132:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &a, &b);
         ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5112 KB Output is correct
2 Correct 7 ms 5112 KB Output is correct
3 Correct 6 ms 5240 KB Output is correct
4 Correct 7 ms 5368 KB Output is correct
5 Correct 7 ms 5368 KB Output is correct
6 Correct 7 ms 5240 KB Output is correct
7 Correct 8 ms 5368 KB Output is correct
8 Correct 7 ms 5368 KB Output is correct
9 Correct 7 ms 5240 KB Output is correct
10 Correct 7 ms 5240 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5112 KB Output is correct
2 Correct 7 ms 5112 KB Output is correct
3 Correct 6 ms 5240 KB Output is correct
4 Correct 7 ms 5368 KB Output is correct
5 Correct 7 ms 5368 KB Output is correct
6 Correct 7 ms 5240 KB Output is correct
7 Correct 8 ms 5368 KB Output is correct
8 Correct 7 ms 5368 KB Output is correct
9 Correct 7 ms 5240 KB Output is correct
10 Correct 7 ms 5240 KB Output is correct
11 Correct 60 ms 11128 KB Output is correct
12 Correct 62 ms 11940 KB Output is correct
13 Correct 93 ms 13304 KB Output is correct
14 Correct 78 ms 16120 KB Output is correct
15 Correct 87 ms 17152 KB Output is correct
16 Correct 100 ms 22136 KB Output is correct
17 Correct 105 ms 24796 KB Output is correct
18 Correct 103 ms 22776 KB Output is correct
19 Correct 105 ms 25672 KB Output is correct
20 Correct 60 ms 11384 KB Output is correct
21 Correct 56 ms 11256 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5112 KB Output is correct
2 Correct 7 ms 5112 KB Output is correct
3 Correct 6 ms 5240 KB Output is correct
4 Correct 7 ms 5368 KB Output is correct
5 Correct 7 ms 5368 KB Output is correct
6 Correct 7 ms 5240 KB Output is correct
7 Correct 8 ms 5368 KB Output is correct
8 Correct 7 ms 5368 KB Output is correct
9 Correct 7 ms 5240 KB Output is correct
10 Correct 7 ms 5240 KB Output is correct
11 Correct 60 ms 11128 KB Output is correct
12 Correct 62 ms 11940 KB Output is correct
13 Correct 93 ms 13304 KB Output is correct
14 Correct 78 ms 16120 KB Output is correct
15 Correct 87 ms 17152 KB Output is correct
16 Correct 100 ms 22136 KB Output is correct
17 Correct 105 ms 24796 KB Output is correct
18 Correct 103 ms 22776 KB Output is correct
19 Correct 105 ms 25672 KB Output is correct
20 Correct 60 ms 11384 KB Output is correct
21 Correct 56 ms 11256 KB Output is correct
22 Correct 207 ms 25720 KB Output is correct
23 Correct 189 ms 24056 KB Output is correct
24 Correct 173 ms 23928 KB Output is correct
25 Correct 203 ms 28864 KB Output is correct
26 Correct 217 ms 25420 KB Output is correct
27 Correct 173 ms 24184 KB Output is correct
28 Correct 63 ms 9080 KB Output is correct
29 Correct 105 ms 12152 KB Output is correct
30 Correct 104 ms 12280 KB Output is correct
31 Correct 105 ms 12600 KB Output is correct
32 Correct 155 ms 18356 KB Output is correct