1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
|
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<algorithm>
#define rep(i,x,y) for(register int i=x;i<=y;++i)
#define repd(i,x,y) for(register int i=x;i>=y;--i)
#define ll long long
using namespace std;
const int N=1e6+7;
int rt[N<<5],lson[N<<5],rson[N<<5],root[N];
int n,m,cnt;
inline void (int &o,int l,int r){
o=++cnt;
if(l==r){scanf("%d",&rt[o]);return ;}
int mid=l+r>>1;
build(lson[o],l,mid);
build(rson[o],mid+1,r);
}
inline void update(int pre,int &o,int l,int r,int k,int x){
o=++cnt;rt[o]=rt[pre];lson[o]=lson[pre];rson[o]=rson[pre];
if(l==r){rt[o]=x;return ;}
int mid=l+r>>1;
if(k<=mid)update(lson[pre],lson[o],l,mid,k,x);
else update(rson[pre],rson[o],mid+1,r,k,x);
}
inline int query(int o,int l,int r,int k){
if(l==r)return rt[o];
int mid=l+r>>1;
if(k<=mid)return query(lson[o],l,mid,k);
return query(rson[o],mid+1,r,k);
}
int main(){
scanf("%d%d",&n,&m);
build(root[0],1,n);
rep(i,1,m){
int pre,op,k,x;
scanf("%d%d%d",&pre,&op,&k);
if(op==1){scanf("%d",&x);update(root[pre],root[i],1,n,k,x);}
else {printf("%dn",query(root[pre],1,n,k));root[i]=root[pre];}
}
return 0;
}
|
近期评论