Submission #793847

#	Time	Username	Problem	Language	Result	Execution time	Memory
793847		winter0101	Bitaro's travel (JOI23_travel)	C++14	100 / 100	288 ms	43948 KiB

travel

#include<bits/stdc++.h>
using namespace std;
#define all(fl) fl.begin(),fl.end()
#define pb push_back
#define fi first
#define se second
#define for1(i,j,k) for(int i=j;i<=k;i++)
#define for2(i,j,k) for(int i=j;i>=k;i--)
#define for3(i,j,k,l) for(int i=j;i<=k;i+=l)
#define lb lower_bound
#define ub upper_bound
#define sz(a) (int)a.size()
#define pii pair<int,int>
#define pli pair<long long,int>
#define gcd __gcd
#define lcm(x,y) x*y/__gcd(x,y)
#define pil pair<int,long long>
#define pll pair<long long,long long>
#define eb emplace_back
const int maxn=2e5+9;
long long a[maxn];
long long b[maxn];
long long c[maxn];
int st1[maxn][21];
int st2[maxn][21];
long long get(int l,int r){
if (l==r)return 0;
return c[r]-c[l];
}
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    //freopen("temp.INP","r",stdin);
    //freopen("temp.OUT","w",stdout);
    int n;
    cin>>n;
    for1(i,1,n){
    cin>>a[i];
    }
    for1(i,2,n){
    c[i]=c[i-1]+a[i]-a[i-1];
    }
    for1(i,1,n-1){
    //2*val[i]>sum-val[i]
    long long val=(a[i+1]-a[i])*2;
    int l=i+2,r=n;
    st1[i][0]=n+1;
    while (l<=r){
    int mid=(l+r)/2;
    //cout<<l<<" "<<r<<" "<<mid<<" "<<val<<'\n';
    if (get(i,mid)>=val){
    st1[i][0]=mid;
    r=mid-1;
    }
    else l=mid+1;
    }
    }
    //cout<<st1[1][0]<<'\n';
    st1[n+1][0]=n+1;
    st1[n][0]=n;
    for1(j,1,20){
    for1(i,1,n){
    if (i+(1<<j)-1>n)break;
    st1[i][j]=max(st1[i][j-1],st1[i+(1<<(j-1))][j-1]);
    }
    }
    st2[1][0]=1;
    for1(i,2,n){
    long long val=(a[i]-a[i-1])*2;
    int l=1,r=i-2;
    st2[i][0]=0;
    while (l<=r){
        int mid=(l+r)/2;
        if (get(mid,i)>val){
        st2[i][0]=mid;
        l=mid+1;
        }
        else r=mid-1;
    }
    }
    //cout<<st2[5][0];
    for1(j,1,20){
    for1(i,1,n){
    if (i+(1<<j)-1>n)break;
    st2[i][j]=min(st2[i][j-1],st2[i+(1<<(j-1))][j-1]);
    }
    }
    for1(i,1,n){
    int l=i,r=i,nw=i;
    while (true){
        if (l==1&&r==n)break;
        if (l==1){
        b[i]+=get(nw,n);
        break;
        }
        if (r==n){
        b[i]+=get(1,nw);
        break;
        }
        long long d1=get(l-1,nw),d2=get(nw,r+1);
        //cout<<l<<" "<<r<<'\n';
        if (d1<=d2){
        nw=l-1;
        //cout<<l<<"->"<<l-1<<'\n';
        l--;
        if (l==1){
            b[i]+=d1;
            continue;
        }
        int pos=nw;
        for2(j,20,0){
        if (pos-(1<<j)+1<=0)continue;
        if (st1[pos-(1<<j)+1][j]<=r+1){
            pos=(pos-(1<<j)+1);
        }
        }
        //cerr<<pos<<" "<<nw<<'\n';
        //if (pos>nw)cout<<"v";
        b[i]+=get(pos,nw)+d1;
        nw=pos;
        l=nw;
        }
        else {
        //cout<<r<<"->"<<r+1<<'\n';
        r++;
        nw=r;
        if (r==n){
            b[i]+=d2;
            continue;
        }
        int pos=nw;
        for2(j,20,0){
        if (pos+(1<<j)-1>n)continue;
        if (st2[pos][j]>=l-1){
            pos=pos+(1<<j)-1;
        }
        }
        b[i]+=get(nw,pos)+d2;
        //cout<<nw<<" "<<pos<<'\n';
        nw=pos;
        r=nw;
        }
    }
    //cout<<b[i]<<'\n';
    }
    int q;
    cin>>q;
    for1(i,1,q){
    int x;
    cin>>x;
    //continue;
    if (x<=a[1])cout<<b[1]+a[1]-x<<'\n';
    else if (x>=a[n])cout<<b[n]+x-a[n]<<'\n';
    else {
    int l=1,r=n,ans=1;
    while (l<=r){
        int mid=(l+r)/2;
        if (a[mid]<=x){
            ans=mid;
            l=mid+1;
        }
        else r=mid-1;
    }
    long long d1=x-a[ans],d2=a[ans+1]-x;
    if (d1<=d2){
        cout<<d1+b[ans]<<'\n';
    }
    else cout<<d2+b[ans+1]<<'\n';
    }
    }

}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 30 / 30
• Subtask 4: 55 / 55