Submission #960334

#	Time	Username	Problem	Language	Result	Execution time	Memory
960334		firewater	Abracadabra (CEOI22_abracadabra)	C++14	0 / 100	125 ms	26192 KiB

Main

#include<bits/stdc++.h>
#define ll long long
#define fs first
#define sn second
#define N 202400
using namespace std;
int n,m,x,y,z,now,sav,v[N],a[N],nx[N],sz[N],ans[N],p[N];
tuple<int,int,int>q[N];
stack<int>st;
struct Tree
{
    int c[N];
    void add(int x,int y)
    {
        for(;x<=n;x+=x&-x)
            c[x]+=y;
        return;
    }
    int ask(int x)
    {
        int sum=0;
        for(;x;x-=x&-x)
            sum+=c[x];
        return sum;
    }
}T;
int get(int x)
{
    int l,r;
    l=1;
    r=n;
    while(l<r){
        int mid=l+r>>1;
        if(T.ask(mid)>=x)r=mid;
        else l=mid+1;
    }
    return l;
}
int main()
{
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;++i){
        scanf("%d",&a[i]);
        v[a[i]]=i;
    }
    for(int i=1;i<=m;++i){
        scanf("%d%d",&x,&y);
        q[i]=tie(x,y,i);
    }
    sort(q+1,q+1+m);
    now=1;
    while(now<=m&&get<0>(q[now])==0){
        tie(x,y,z)=q[now];
        ans[z]=a[y];
        now++;
    }
    st.push(n+1);
    a[n+1]=2000000000;
    for(int i=n;i>0;--i){
        while(a[st.top()]<a[i])st.pop();
        nx[i]=st.top();
        sz[i]=nx[i]-i;
        st.push(i);
    }
    while(st.top()!=n+1){
        x=st.top();
        st.pop();
        p[x]=1;
        T.add(a[x],sz[x]);
    }
    for(int i=1;i<=n;++i){
        x=get(n/2+1);
        if(T.ask(x-1)==n/2)break;
        x=v[x];
        T.add(a[x],-sz[x]);
        sz[x]=n/2-T.ask(a[x]-1);
        T.add(a[x],sz[x]);

        y=x+sz[x];
        // printf("%d %d %d\n",x,y,sz[x]);
        while(y<=n&&!p[y]){
            p[y]=1;
            T.add(a[y],sz[y]);
            y=nx[y];
        }
        // for(int i=1;i<=n;++i)
        //     printf("%d ",sz[i]);
        // putchar(10);
        // for(int i=1;i<=n;++i)
        //     printf("%d ",T.ask(i));
        // putchar(10);

        while(now<=m&&get<0>(q[now])==i){
            tie(x,y,z)=q[now];
            sav=get(y);
            ans[z]=a[v[sav]+(y-T.ask(sav-1))-1];
            now++;
        }
    }
    while(now<=m){
        tie(x,y,z)=q[now];
        sav=get(y);
        ans[z]=a[v[sav]+(y-T.ask(sav-1))-1];
        now++;
    }
    for(int i=1;i<=m;++i)
        printf("%d\n",ans[i]);
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int get(int)':
Main.cpp:33:18: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   33 |         int mid=l+r>>1;
      |                 ~^~
Main.cpp: In function 'int main()':
Main.cpp:41:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |     scanf("%d%d",&n,&m);
      |     ~~~~~^~~~~~~~~~~~~~
Main.cpp:43:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |         scanf("%d",&a[i]);
      |         ~~~~~^~~~~~~~~~~~
Main.cpp:47:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |         scanf("%d%d",&x,&y);
      |         ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 40
• Subtask 3: 0 / 25
• Subtask 4: 0 / 25