Submission #887887

#	Time	Username	Problem	Language	Result	Execution time	Memory
887887		1L1YA	Rainforest Jumps (APIO21_jumps)	C++17	0 / 100	5 ms	41304 KiB

jumps

//1L1YA
#include "jumps.h"
#include<bits/stdc++.h>
using namespace std;
#define ll           long long
#define Pb           push_back
#define dokme(x)     cout << x << endl, exit(0)
#define pii          pair<int,int>
#define F            first
#define S            second
#define endl         '\n'
#define sep          ' '
#define all(x)       x.begin(),x.end()
#define FastIO       ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define lc           id<<1
#define rc           lc|1

const int N=2e5+5;
const int lg=23;

int n,a[N],lst[N],nxt[N],seg[N<<2],sp1[lg][N],sp2[lg][N];

void modify(int pos,int val,int id=1,int l=1,int r=n+1){
    if(r-l==1){
        seg[id]=val;
        return;
    }
    int mid=l+r>>1;
    if(pos<mid)    modify(pos,val,lc,l,mid);
    else    modify(pos,val,rc,mid,r);
    seg[id]=max(seg[lc],seg[rc]);
}

int get(int ql,int qr,int id=1,int l=1,int r=n+1){
    if(qr<=l || ql>=r)    return 0;
    if(ql<=l && r<=qr)    return seg[id];
    int mid=l+r>>1;
    return max(get(ql,qr,lc,l,mid),get(ql,qr,rc,mid,r));
}

void init(int m, std::vector<int> h) {
    n=m;
    for(int i=1;i<=n;i++)
        a[i]=h[i-1];
    a[0]=a[n+1]=n+1;
    vector<int> st;
    st.Pb(0);
    for(int i=1;i<=n;i++){
        while(a[st.back()]<a[i])
            st.pop_back();
        lst[i]=st.back();
        st.Pb(i);
    }
    st.clear();
    st.Pb(n+1);
    for(int i=n;i;i--){
        while(a[st.back()]<a[i])
            st.pop_back();
        nxt[i]=st.back();
        st.Pb(i);
    }
    for(int i=1;i<=n;i++){
        sp1[0][a[i]]=min(a[lst[i]],a[nxt[i]]);
        sp2[0][a[i]]=max(a[lst[i]],a[nxt[i]]);
    }
    sp1[0][n+1]=sp2[0][n+1]=n+1;
    for(int i=n+1;i;i--)
        for(int j=1;j<lg;j++){
            sp1[j][i]=sp1[j-1][sp1[j-1][i]];
            sp2[j][i]=sp2[j-1][sp2[j-1][i]];
        }
    for(int i=1;i<=n;i++)
        modify(i,a[i]);
}

int dist(int s,int e){
    int ans=0;
    for(int i=lg-1;~i;i--)
        if(sp2[i][s]<e)
            s=sp2[i][s],ans+=1<<i;
    if(sp2[0][s]==e)
        return ans+1;
    for(int i=lg-1;~i;i--)
        if(sp1[i][s]<e)
            s=sp1[i][s],ans+=1<<i;
    return ans+1;
}

int minimum_jumps(int l1, int r1, int l2, int r2){
    l1++;r1++;l2++;r2++;
    int mx=get(l2,r2+1);
    if(get(r1,l2)>mx)
        return -1;
    int l=0,r=r1;
    while(r-l>1){
        int mid=l+r>>1;
        if(get(mid,r1+1)<mx)    r=mid;
        else    l=mid;
    }
    int k=r,x=get(max(l1,k),r1+1);
    mx=get(max(l1,k),l2);
    int ans=dist(x,mx)+1;
    if(k<=l1){
        l=1,r=l1;
        while(r-l>1){
            int mid=l+r>>1;
            if(get(mid,l1)<mx)    r=mid;
            else    l=mid;
        }
        if(l>k)
            ans=min(ans,dist(x,a[l])+1);
    }
    return ans;
}
/*
int main() {
  int N, Q;
  assert(2 == scanf("%d %d", &N, &Q));
  std::vector<int> H(N);
  for (int i = 0; i < N; ++i) {
    assert(1 == scanf("%d", &H[i]));
  }
  init(N, H);

  for (int i = 0; i < Q; ++i) {
    int A, B, C, D;
    assert(4 == scanf("%d %d %d %d", &A, &B, &C, &D));
    printf("%d\n", minimum_jumps(A, B, C, D));
  }
  return 0;
}*/

Compilation message (stderr)

jumps.cpp: In function 'void modify(int, int, int, int, int)':
jumps.cpp:28:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   28 |     int mid=l+r>>1;
      |             ~^~
jumps.cpp: In function 'int get(int, int, int, int, int)':
jumps.cpp:37:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   37 |     int mid=l+r>>1;
      |             ~^~
jumps.cpp: In function 'int minimum_jumps(int, int, int, int)':
jumps.cpp:96:18: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   96 |         int mid=l+r>>1;
      |                 ~^~
jumps.cpp:106:22: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  106 |             int 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