Submission #799369

#	Time	Username	Problem	Language	Result	Execution time	Memory
799369		vjudge1	Rainforest Jumps (APIO21_jumps)	C++17	0 / 100	215 ms	43668 KiB

jumps

#include "jumps.h"
#include<bits/stdc++.h>
#define TASKNAME "codeforce"
#define pb push_back
#define pli pair<int,int>
#define fi first
#define se second
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL);
using namespace std;
using ll=long long;
const ll maxN=1e5+10;
const ll inf=1e18;
const ll mod=1e9+7;
ll n,a[maxN],l[maxN],r[maxN];
pli st[4*maxN];
void upd(ll pos,ll val,ll id=1,ll l=1,ll r=n)
{
    if(l==r)
    {
        st[id]={val,pos};
        return;
    }
    ll mid=l+r>>1;
    if(pos<=mid) upd(pos,val,id*2,l,mid);
    else upd(pos,val,id*2+1,mid+1,r);
    st[id]=max(st[id*2],st[id*2+1]);
}
pli get(ll i,ll j,ll id=1,ll l=1,ll r=n)
{
    if(j<l||r<i) return {0,0};
    if(i<=l&&r<=j) return st[id];
    ll mid=l+r>>1;
    return max(get(i,j,id*2,l,mid),get(i,j,id*2+1,mid+1,r));
}
vector<ll>g[maxN];
ll d[maxN];
void dfs(ll u)
{
    for(int v:g[u])
    {
        d[v]=d[u]+1;
        dfs(v);
    }
}
int par[maxN][18];
void init(int N,vector<int> H)
{
    n=N;
    for(int i=1;i<=n;i++) a[i]=H[i-1],upd(i,a[i]);
    vector<int>dq;
    a[0]=inf;
    for(int i=1;i<=n;i++)
    {
        while(!dq.empty()&&a[i]>a[dq.back()]) dq.pop_back();
        if(dq.size()==0) l[i]=0;
        else l[i]=dq.back();
        dq.pb(i);
    }
    dq.clear();
    ll rr=0;
    for(int i=n;i>=1;i--)
    {
        while(!dq.empty()&&a[i]>a[dq.back()]) dq.pop_back();
        if(dq.size()==0) r[i]=0;
        else r[i]=dq.back();
        dq.pb(i);
        if(l[i]==0&&r[i]==0) rr=i;
    }
    for(int i=1;i<=n;i++)
    {
        bool sw=0;
        if(a[l[i]]>a[r[i]]) swap(l[i],r[i]),sw=true;
        g[l[i]].pb(i);
        par[i][0]=r[i]==0?l[i]:r[i];
        if(sw) swap(l[i],r[i]);
    }
    dfs(rr);
    for(int j=1;j<=17;j++)
    {
        for(int i=1;i<=n;i++)
        {
            par[i][j]=par[par[i][j-1]][j-1];
        }
    }
}
int minimum_jumps(int A, int B, int C, int D)
{
    A++,B++,C++,D++;
    if(l[C]>=B) return -1;
    ll x=B;
    ll ans=0;
    for(int i=17;i>=0;i--)
    {
        ll cc=par[x][i];
        if(a[cc]<=a[C]) x=cc,ans+=1<<i;
    }
    return ans+d[x]-d[C];
}
/*int main()
{
    fastio
    //freopen(TASKNAME".INP","r",stdin);
    //freopen(TASKNAME".OUT","w",stdout);
    //init(7, {3, 2, 1, 6, 4, 5, 7});
    //cout << minimum_jumps(4, 4, 6, 6)<<' '<<minimum_jumps(1, 3, 6, 6)<<' '<<minimum_jumps(0, 1, 2, 2);
}*/

Compilation message (stderr)

jumps.cpp: In function 'void upd(ll, ll, ll, ll, ll)':
jumps.cpp:23:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   23 |     ll mid=l+r>>1;
      |            ~^~
jumps.cpp: In function 'std::pair<int, int> get(ll, ll, ll, ll, ll)':
jumps.cpp:32:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   32 |     ll mid=l+r>>1;
      |            ~^~

• Subtask 1: 0 / 4
• Subtask 2: 0 / 8
• Subtask 3: 0 / 13
• Subtask 4: 0 / 12
• Subtask 5: 0 / 23
• Subtask 6: 0 / 21
• Subtask 7: 0 / 19