Submission #957900

#	Time	Username	Problem	Language	Result	Execution time	Memory
957900		vjudge1	Abracadabra (CEOI22_abracadabra)	C++17	100 / 100	542 ms	48388 KiB

Main

#include<stdio.h>
#include<stdlib.h>

#define N 200004
int n,a[N],t[N],q,sz[N],at[N],*eh[N],eo[N],zz[1000005],nxt[N];

void upd(int p,int k) { for(;p<N;p|=p+1)t[p]+=k; }
int qry(int p) {int z=0;for(;p>0;p&=p-1)z+=t[p-1];return z;}

void add(int p,int k) { sz[p]=k; upd(p,k); }
void rem(int p) { upd(p,-sz[p]); }

int grp(int x)
{
    int p=0,v=0;
    for(int j=1<<19;j>0;j>>=1) if(p+j<=N&&v+t[p+j-1]<x)p+=j,v+=t[p-1];
    return p;
}

void append(int i,int j)
{
    int o=eo[i]++;
    if(o>=2&&(o&o-1)==0)eh[i]=(int*)realloc(eh[i],2*o*sizeof**eh);
    eh[i][o]=j;
}

void shuffle()
{
    int g1=grp(n/2),g2=grp(n/2+1);
    if(g1!=g2)return;
    int rl=qry(g1);
    int st=at[g1];
    int md=n/2-rl+at[g1];
    int ed=at[g1]+sz[g1];
    for(int j=md;j<ed;j=nxt[j])add(a[j],(ed<nxt[j]?ed:nxt[j])-j);
    rem(g1);
    add(g1,n/2-rl);
}

int main()
{
    scanf("%d%d",&n,&q);
    for(int i=1;i<=n;++i)scanf("%d",a+i),at[a[i]]=i;

    {
        static int s[N];int so=0;
        for(int i=1;i<=n;++i)
        {
            while(so&&a[i]>a[s[so]])nxt[s[so--]]=i;
            s[++so]=i;
        }
        while(so)nxt[s[so--]]=n+1;
        for(int i=1;i<=n;i=nxt[i])add(a[i],nxt[i]-i);
    }

    for(int i=0;i<=n;++i)eh[i]=(int*)malloc(2*sizeof**eh);

    for(int t,p,i=0;i<q;++i)
    {
        scanf("%d%d",&t,&p);
        if(t>n)t=n;
        append(t,i),append(t,p);
    }

    for(int i=0;i<=n;++i)
    {
        for(int j=0;j<eo[i];j+=2)
        {
            int gg=grp(eh[i][j+1]);
            int idx=eh[i][j+1]-qry(gg);
            zz[eh[i][j]]=a[at[gg]+idx-1];
        }
        shuffle();
    }

    for(int i=0;i<q;++i)printf("%d\n",zz[i]);

    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'void append(int, int)':
Main.cpp:23:18: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   23 |     if(o>=2&&(o&o-1)==0)eh[i]=(int*)realloc(eh[i],2*o*sizeof**eh);
      |                 ~^~
Main.cpp: In function 'void shuffle()':
Main.cpp:32:9: warning: unused variable 'st' [-Wunused-variable]
   32 |     int st=at[g1];
      |         ^~
Main.cpp: In function 'int main()':
Main.cpp:42:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |     scanf("%d%d",&n,&q);
      |     ~~~~~^~~~~~~~~~~~~~
Main.cpp:43:31: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |     for(int i=1;i<=n;++i)scanf("%d",a+i),at[a[i]]=i;
      |                          ~~~~~^~~~~~~~~~
Main.cpp:60:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |         scanf("%d%d",&t,&p);
      |         ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 40 / 40
• Subtask 3: 25 / 25
• Subtask 4: 25 / 25