Submission #587736

#	Time	Username	Problem	Language	Result	Execution time	Memory
587736		krit3379	Rainforest Jumps (APIO21_jumps)	C++17	44 / 100	2441 ms	36132 KiB

jumps

#include<bits/stdc++.h>
#include"jumps.h"
using namespace std;
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define N 200005

int t[4*N],arr[N],up[20][N],dow[20][N],n;

void cre(int x,int l,int r){
    if(l==r){t[x]=arr[l];return ;}
    int mid=(l+r)/2;
    cre(x*2,l,mid);
    cre(x*2+1,mid+1,r);
    t[x]=max(t[x*2],t[x*2+1]);
}

int sol(int x,int l,int r,int ll,int rr){
    if(l>rr||ll>r||ll>rr)return 0;
    if(ll<=l&&r<=rr)return t[x];
    int mid=(l+r)/2;
    return max(sol(x*2,l,mid,ll,rr),sol(x*2+1,mid+1,r,ll,rr));
}

void init(int nn,vector<int> h){
    int i,j,l,r,mid,val;
    n=nn;
    for(i=0;i<n;i++)arr[i+1]=h[i];
    cre(1,1,n);
    arr[n+1]=n+1;
    for(i=0;i<20;i++)for(j=0;j<=n+1;j++)up[i][j]=dow[i][j]=n+1;
    for(i=1;i<=n;i++){
        l=1,r=i-1;
        while(l<=r){
            mid=(l+r)/2;
            if(sol(1,1,n,mid,i-1)>arr[i])dow[0][arr[i]]=arr[mid],l=mid+1;
            else r=mid-1;
        }
        l=i+1,r=n;
        while(l<=r){
            mid=(l+r)/2;
            if(sol(1,1,n,i+1,mid)>arr[i])up[0][arr[i]]=arr[mid],r=mid-1;
            else l=mid+1;
        }
        if(up[0][arr[i]]<dow[0][arr[i]])swap(up[0][arr[i]],dow[0][arr[i]]);
    }
    for(i=1;i<20;i++)for(j=1;j<=n;j++){
        up[i][j]=up[i-1][up[i-1][j]];
        dow[i][j]=dow[i-1][dow[i-1][j]];
    }
    return ;
}

int minimum_jumps(int a,int b,int c,int d){
    a++,b++,c++,d++;
    int i,l,r,mid,ml,mm,mr,now,val,ans=0;
    mm=sol(1,1,n,c+1,d-1);
    mr=sol(1,1,n,c,d);
    if(mm>mr)return -1;
    l=c,r=d;
    while(l<=r){
        mid=(l+r)/2;
        if(sol(1,1,n,c,mid)>mm)ml=arr[mid],r=mid-1;
        else l=mid+1;
    }
    l=a,r=b;
    now=n+1;
    while(l<=r){
        mid=(l+r)/2;
        val=sol(1,1,n,mid,b);
        if(val<mr)now=val,r=mid-1;
        else l=mid+1;
    }
    if(now>mr)return -1;
    for(i=19;i>=0;i--)if(up[i][now]<ml)ans+=1<<i,now=up[i][now];
    if(up[0][now]>=ml&&up[0][now]<=mr)return ans+1;
    for(i=19;i>=0;i--)if(dow[i][now]<ml)ans+=1<<i,now=dow[i][now];
    if(dow[0][now]>=ml&&dow[0][now]<=mr)return ans+1;
    return -1;
}

Compilation message (stderr)

jumps.cpp: In function 'void init(int, std::vector<int>)':
jumps.cpp:26:21: warning: unused variable 'val' [-Wunused-variable]
   26 |     int i,j,l,r,mid,val;
      |                     ^~~
jumps.cpp: In function 'int minimum_jumps(int, int, int, int)':
jumps.cpp:78:5: warning: 'ml' may be used uninitialized in this function [-Wmaybe-uninitialized]
   78 |     if(dow[0][now]>=ml&&dow[0][now]<=mr)return ans+1;
      |     ^~

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