Codeforces Round #307 (Div. 2) E. GukiZ and GukiZiana 分块
Professor GukiZ was playing with arrays again and accidentally discovered new function, which he called GukiZiana. For given array a, indexed with integers from 1 to n, and number y, GukiZiana(a, y) represents maximum value of j - i, such that aj = ai = y. If there is no y as an element in a, then GukiZiana(a, y) is equal to - 1. GukiZ also prepared a problem for you. This time, you have two types of queries:
- First type has form 1 l r x and asks you to increase values of all ai such that l ≤ i ≤ r by the non-negative integer x.
- Second type has form 2 y and asks you to find value of GukiZiana(a, y).
For each query of type 2, print the answer and make GukiZ happy!
The first line contains two integers n, q (1 ≤ n ≤ 5 * 105, 1 ≤ q ≤ 5 * 104), size of array a, and the number of queries.
The second line contains n integers a1, a2, ... an (1 ≤ ai ≤ 109), forming an array a.
Each of next q lines contain either four or two numbers, as described in statement:
If line starts with 1, then the query looks like 1 l r x (1 ≤ l ≤ r ≤ n, 0 ≤ x ≤ 109), first type query.
If line starts with 2, then th query looks like 2 y (1 ≤ y ≤ 109), second type query.
For each query of type 2, print the value of GukiZiana(a, y), for y value for that query.
4 3
1 2 3 4
1 1 2 1
1 1 1 1
2 3
2
2 3
1 2
1 2 2 1
2 3
2 4
0
-1
思路:分块,map超时,MLE,vector+二分即可;
#include<bits/stdc++.h> using namespace std; #define ll long long #define pi (4*atan(1.0)) #define eps 1e-14 #define bug(x,y) cout<<"bug"<<x<<" "<<y<<endl; #define bug(x) cout<<"xxx "<<x<<endl; const int N=5e5+10,M=1e6+10,inf=2e9+10,mod=6; const ll INF=1e18+10; ll a[N],add[N]; int n,q,ka,pos[N]; vector<pair<ll,int> >vec[710]; int cmp(pair<ll,int> a,pair<ll,int> b) { if(a.first==b.first) return a.second<b.second; return a.first<b.first; } int ansl,ansr; void brute(int l,int r,int pos) { vec[pos].clear(); for(int i=l; i<=r; i++) vec[pos].push_back(make_pair(a[i],i)); sort(vec[pos].begin(),vec[pos].end(),cmp); } void brutef(int l,int r,int pos,ll x) { for(int i=l; i<=r; i++) { if(add[pos]+a[i]==x) { ansl=min(ansl,i); ansr=max(ansr,i); } } } void update(int l,int r,ll x) { if(pos[l]==pos[r]) { for(int i=l;i<=r;i++) a[i]+=x; brute((pos[l]-1)*ka+1,pos[l]*ka,pos[l]); return; } for(int i=pos[l]+1; i<=pos[r]-1; i++) add[i]+=x; for(int i=l; i<=min(r,pos[l]*ka); i++) a[i]+=x; brute((pos[l]-1)*ka+1,pos[l]*ka,pos[l]); for(int i=max(l,(pos[r]-1)*ka+1); i<=r; i++) a[i]+=x; if(pos[r]<=n/ka) brute((pos[r]-1)*ka+1,pos[r]*ka,pos[r]); } void slove(ll x) { ansl=n+1; ansr=0; for(int i=1; i<=n/ka; i++) { int l1=0,l2=0,l=-1; int r1=ka-1,r2=ka-1,r=-1; while(l1<=r1) { int mid=(l1+r1)>>1; if(vec[i][mid].first<x-add[i]) l1=mid+1; else if(vec[i][mid].first==x-add[i]) { l=mid; r1=mid-1; } else r1=mid-1; } while(l2<=r2) { int mid=(l2+r2)>>1; if(vec[i][mid].first<x-add[i]) l2=mid+1; else if(vec[i][mid].first==x-add[i]) { r=mid; l2=mid+1; } else r2=mid-1; } if(l!=-1) { ansl=min(ansl,vec[i][l].second); ansr=max(ansr,vec[i][r].second); } } brutef((n/ka)*ka+1,n,n/ka+1,x); //cout<<ansr<<" "<<ansl<<endl; if(ansl==n+1) puts("-1"); else printf("%d\n",ansr-ansl); } int main() { scanf("%d%d",&n,&q); for(int i=1; i<=n; i++) scanf("%lld",&a[i]); ka=sqrt(n); for(int i=1; i<=n; i++) pos[i]=(i-1)/ka+1; for(int i=1; i<=n/ka; i++) brute(ka*(i-1)+1,ka*i,i); while(q--) { int flag,l,r; ll x; scanf("%d",&flag); if(flag==1) { scanf("%d%d%lld",&l,&r,&x); update(l,r,x); } else { scanf("%lld",&x); slove(x); } } return 0; }