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| #include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
using namespace std;
#define REP(i,e,s) for(register int i=(e); i<=(s); i++)
#define DREP(i,e,s) for(register int i=(e); i>=(s); i--)
#define ll long long
#define DE(...) fprintf(stderr,__VA_ARGS__)
#define DEBUG(a) DE("DEBUG: %d\n",a)
#define file(a) freopen(a".in","r",stdin);freopen(a".out","w",stdout)
int read() {
int x=0,f=1,ch=getchar();
while(ch>'9'||ch<'0'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
return x*f;
}
const int MAXN=200000+10,MAXM=MAXN*18;;
int rt[MAXM],a[MAXN];
struct President_Tree {
int cnt,ls[MAXM],rs[MAXM],sum[MAXM];
President_Tree() {
cnt=0;
}
void build(int &p,int l,int r) {
p=++cnt;
if(l==r) return ;
int mid=(l+r)>>1;
build(ls[p],l,mid);
build(rs[p],mid+1,r);
}
void change(int &p,int l,int r,int u,int x) {
p=++cnt,ls[p]=ls[u],rs[p]=rs[u],sum[p]=sum[u]+1;
if(l==r) return ;
int mid=(l+r)>>1;
if(x<=mid) change(ls[p],l,mid,ls[u],x);
else change(rs[p],mid+1,r,rs[u],x);
}
int ask(int x,int y,int l,int r,int k) {
if(l==r) return l;
int mid=(l+r)>>1;
if(sum[ls[y]]-sum[ls[x]]>=k) return ask(ls[x],ls[y],l,mid,k);
else if(sum[rs[y]]-sum[rs[x]]>=k) return ask(rs[x],rs[y],mid+1,r,k);
return -1;
}
} s;
int main() {
int n=read(),m=read();
REP(i,1,n) a[i]=read();
int sz=n;
s.build(rt[0],1,sz);
REP(i,1,n) s.change(rt[i],1,sz,rt[i-1],a[i]);
while(m--) {
int l=read(),r=read();
int t=s.ask(rt[l-1],rt[r],1,sz,(r-l+1)/2+1);
if(t!=-1) printf("%d\n",t);
else puts("0");
}
return 0;
}
|
