Submission #587647

#	Time	Username	Problem	Language	Result	Execution time	Memory
587647		krit3379	Rainforest Jumps (APIO21_jumps)	C++17	4 / 100	2512 ms	20388 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],nxt[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;
    n=nn;
    for(i=0;i<n;i++)arr[i+1]=h[i];
    arr[n+1]=1e9;
    cre(1,1,n);
    for(i=0;i<20;i++)for(j=0;j<=n+1;j++)nxt[i][j]=n+1;
    for(i=1;i<=n;i++){
        l=i+1,r=n;
        while(l<=r){
            mid=(l+r)/2;
            if(sol(1,1,n,i+1,mid)>arr[i])nxt[0][i]=mid,r=mid-1;
            else l=mid+1;
        }
    }
    for(i=1;i<20;i++)for(j=1;j<=n;j++)nxt[i][j]=nxt[i-1][nxt[i-1][j]];
    return ;
}

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

Compilation message (stderr)

jumps.cpp: In function 'int minimum_jumps(int, int, int, int)':
jumps.cpp:71:9: warning: 'val' may be used uninitialized in this function [-Wmaybe-uninitialized]
   71 |         if(sol(1,1,n,mid,b)<=val)pos=mid,l=mid+1;
      |         ^~

• Subtask 1: 4 / 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