Submission #937218

#	Time	Username	Problem	Language	Result	Execution time	Memory
937218		sleepntsheep	Rigged Roads (NOI19_riggedroads)	C++17	58 / 100	2063 ms	30820 KiB

riggedroads

#include<stdio.h>
int hi(int a,int b){return a>b?a:b;}
unsigned X=12345;int rand_(){return(X*=3)>>1;}
int(*compar)(int,int);void sort(int*aa,int l,int r){ while(l<r){ int i=l,j=l,k=r,t,p=aa[l+rand_()%(r-l)]; while(j<k)switch(compar(aa[j],p)){case 0:++j;break;case -1:t=aa[i],aa[i]=aa[j],aa[j]=t,++i,++j;break;case 1:t=aa[--k],aa[k]=aa[j],aa[j]=t;break;}sort(aa,l,i);l=k; }}

#define N 300005


int ttt[N],n,m,h[N],e[N<<1][2],ne,y[N],id,pp[N],jj[N],ee[N],dd[N],w[N],tin[N],tout[N],timer;
void _l(int u,int v){e[++ne][0]=v,e[ne][1]=h[u],h[u]=ne;}

void __u(int*t,int p,int k){ for(;p<N;p+=p&-p)t[p]+=k; }
int __q(int*t,int p){int z=0;for(;p;p-=p&-p)z+=t[p];return z;}
int __s(int*t,int k){int p=0,v=0,j=1<<20;for(;j>>=1;)if(p+j<N&&v+t[p+j]<k)v+=t[p+=j];return p+1;}

void doedge(int v,int k){
    __u(ttt,tin[v],k);
    __u(ttt,tout[v]+1,-k);
}

void dfs(int u,int p){
    tin[u]=timer++;
    for(int v,j=h[u];j;j=e[j][1])if((v=e[j][0])!=p&&y[(j+1)/2]){
        dd[v]=dd[pp[v]=u]+1;
        ee[v]=(j+1)/2;
        pp[v]=u;
        jj[v]=(dd[p]-dd[jj[u]]==dd[jj[u]]-dd[jj[jj[u]]])?jj[jj[u]]:u;
        dfs(v,u);
        doedge(v,1);
    }
    tout[u]=timer-1;
}

int qq(int u,int v){
    if(dd[u]>dd[v])return qq(v,u);
    while(dd[v]>dd[u])
        if(dd[jj[v]]>=dd[u]) v=jj[v];
        else v=pp[v];
    while(u-v)
        if(jj[v]-jj[u])u=jj[u],v=jj[v];
        else u=pp[u],v=pp[v];
    return u;
}

int nx(int u,int aa){
    if(u==1)return -1;
    int base=__q(ttt,tin[u]);
    while(dd[u]>dd[aa]&&__q(ttt,tin[pp[u]])==base){
        u=(dd[jj[u]]>dd[aa]&&__q(ttt,tin[jj[u]])==base)?jj[u]:pp[u];
    }
    return u;
}

int need[N],np;

int c1(int i,int j){return ee[i]<ee[j]?-1:ee[i]>ee[j]?1:0;}

int main(){
    scanf("%d%d",&n,&m);
    for(int u,v,i=1;i<=m;++i)scanf("%d%d",&u,&v),_l(u,v),_l(v,u);
    for(int j,i=1;i<n;++i)scanf("%d",&j),y[j]=1;
    pp[1]=jj[1]=1;dfs(1,1);

    int ord = 1;
    for(int j=1;j<=m;++j){
        int u=e[j*2-1][0],v=e[j*2][0];
        if(dd[v]+1==dd[u]){int t=u;u=v;v=t;}
        if(w[j])continue;
        if(!y[j]){
            int lca=qq(u,v);
            for(int ii=nx(u,lca);~ii&&dd[ii]>dd[lca];ii=nx(ii,lca)) doedge(ii,-1),need[np++]=ii;
            for(int ii=nx(v,lca);~ii&&dd[ii]>dd[lca];ii=nx(ii,lca)) doedge(ii,-1),need[np++]=ii;
            compar=c1;sort(need,0,np);
            for(int i=0;i<np;++i) w[ee[need[i]]]=ord++;
            np=0;
            w[j]=ord++;
        }else{
            w[j]=ord++;
            doedge(v,-1);
        }
    }
    for(int j=1;j<=m;++j)printf("%d ",w[j]);
}

Compilation message (stderr)

riggedroads.cpp: In function 'int main()':
riggedroads.cpp:59:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   59 |     scanf("%d%d",&n,&m);
      |     ~~~~~^~~~~~~~~~~~~~
riggedroads.cpp:60:35: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |     for(int u,v,i=1;i<=m;++i)scanf("%d%d",&u,&v),_l(u,v),_l(v,u);
      |                              ~~~~~^~~~~~~~~~~~~~
riggedroads.cpp:61:32: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   61 |     for(int j,i=1;i<n;++i)scanf("%d",&j),y[j]=1;
      |                           ~~~~~^~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 19 / 19
• Subtask 3: 9 / 9
• Subtask 4: 0 / 10
• Subtask 5: 10 / 10
• Subtask 6: 12 / 12
• Subtask 7: 0 / 32