Submission #649923

#	Time	Username	Problem	Language	Result	Execution time	Memory
649923		ToroTN	Rainforest Jumps (APIO21_jumps)	C++14	100 / 100	1396 ms	84680 KiB

jumps

#include "jumps.h"
#include<bits/stdc++.h>
using namespace std;
#define X first
#define Y second
#include <vector>
int n,h[200005],l[200005][25],r[200005][25],a,b,c,d,mx,node,cnt;
int low[200005][25],high[200005][25],seg[800005],ans;
stack<pair<int,int> > stk;
void build(int tree,int st,int ed)
{
    int md=(st+ed)/2;
    if(st==ed)
    {
        seg[tree]=h[st];
        return;
    }
    build(2*tree,st,md);
    build(2*tree+1,md+1,ed);
    seg[tree]=max(seg[2*tree],seg[2*tree+1]);
}
int query(int tree,int st,int ed,int l,int r)
{
    int md=(st+ed)/2;
    if(st>r||ed<l)return -1e9;
    if(st>=l&&ed<=r)return seg[tree];
    return max(query(2*tree,st,md,l,r),query(2*tree+1,md+1,ed,l,r));
}
void debug(int tree,int st,int ed)
{
    int md=(st+ed)/2;
    if(st==ed)
    {
        printf("%d %d %d %d\n",tree,st,ed,seg[tree]);
        return;
    }
    debug(2*tree,st,md);
    debug(2*tree+1,md+1,ed);
    printf("%d %d %d %d\n",tree,st,ed,seg[tree]);
}
void init(int N, std::vector<int> H) {
    n=N;
    for(int i=1;i<=n;i++)
    {
        h[i]=H[i-1];
    }
    build(1,1,n);
    //debug(1,1,n);
    for(int i=1;i<=n;i++)
    {
        while(!stk.empty())
        {
            if(stk.top().X>h[i])
            {
                break;
            }else
            {
                r[stk.top().Y][0]=i;
                stk.pop();
            }
        }
        stk.push({h[i],i});
    }
    while(!stk.empty())
    {
        stk.pop();
    }
    for(int i=n;i>=1;i--)
    {
        while(!stk.empty())
        {
            if(stk.top().X>h[i])
            {
                break;
            }else
            {
                l[stk.top().Y][0]=i;
                stk.pop();
            }
        }
        stk.push({h[i],i});
    }
    while(!stk.empty())
    {
        stk.pop();
    }
    for(int i=1;i<=n;i++)
    {
        if(l[i][0]!=0&&r[i][0]!=0)
        {
            low[i][0]=l[i][0];
            high[i][0]=r[i][0];
            if(h[l[i][0]]>h[r[i][0]])swap(low[i][0],high[i][0]);
        }else if(l[i][0]!=0||r[i][0]!=0)
        {
            low[i][0]=high[i][0]=max(l[i][0],r[i][0]);
        }
    }
    for(int i=1;i<=20;i++)
    {
        for(int j=1;j<=n;j++)
        {
            l[j][i]=l[l[j][i-1]][i-1];
            r[j][i]=r[r[j][i-1]][i-1];
            low[j][i]=low[low[j][i-1]][i-1];
            high[j][i]=high[high[j][i-1]][i-1];
        }
    }
    // for(int j=0;j<=20;j++)
    // {
    //     printf("%d\n",j);
    //     for(int i=1;i<=n;i++)
    //     {
    //         printf("%d ",r[i][j]);
    //     }
    //     printf("\n");
    //     for(int i=1;i<=n;i++)
    //     {
    //         printf("%d ",l[i][j]);
    //     }
    //     printf("\n");
    //     for(int i=1;i<=n;i++)
    //     {
    //         printf("%d ",low[i][j]);
    //     }
    //     printf("\n");
    //     for(int i=1;i<=n;i++)
    //     {
    //         printf("%d ",high[i][j]);
    //     }
    //     printf("\n");
    // }
}
int minimum_jumps(int A, int B, int C, int D) {
    a=A+1;
    b=B+1;
    c=C+1;
    d=D+1;
    mx=query(1,1,n,c,d);
    node=b;
    if(r[node][0]>=c&&r[node][0]<=d)return 1;
    //printf("mx=%d\n",mx);
    //printf("%d\n",node);
    for(int i=20;i>=0;i--)
    {
        if(l[node][i]!=0)
        {
            if(h[l[node][i]]<mx&&l[node][i]>=a)
            {
                node=l[node][i];
            }
        }
    }
    //printf("%d %d\n",node,ans);
    ans=0;
    if(r[node][0]>=c&&r[node][0]<=d)return ans+1;
    for(int i=20;i>=0;i--)
    {
        if(high[node][i]!=0)
        {
            //printf("high=%d %d\n",i,high[node][i]);
            if(h[high[node][i]]<mx&&high[node][i]<c&&r[high[node][i]][0]<c&&r[high[node][i]][0]!=0)
            {
                node=high[node][i];
                ans+=(1<<i);
            }
        }
    }
    //printf("%d %d\n",node,ans);
    if(h[high[node][0]]<mx)
    {
        node=high[node][0];
        ans+=1;
    }
    if(r[node][0]>=c&&r[node][0]<=d)return ans+1;
    for(int i=20;i>=0;i--)
    {
        if(low[node][i]!=0)
        {
            if(h[low[node][i]]<mx&&low[node][i]<c&&r[low[node][i]][0]<c&&r[low[node][i]][0]!=0)
            {
                node=low[node][i];
                ans+=(1<<i);
            }
        }
    }
    //printf("%d %d\n",node,ans);
    if(h[low[node][0]]<mx)
    {
        node=low[node][0];
        ans+=1;
    }
    if(r[node][0]>=c&&r[node][0]<=d)return ans+1;
    return -1;
}

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