Submission #973558

#	Time	Username	Problem	Language	Result	Execution time	Memory
973558		Tuanlinh123	Rainforest Jumps (APIO21_jumps)	C++17	100 / 100	950 ms	64708 KiB

jumps

// #include "stub.cpp"
#include "jumps.h"
#include<bits/stdc++.h>
#define ll int
#define pll pair<ll, ll>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define ld long double
#define sz(a) ((ll)(a).size())
using namespace std;

const ll maxn=200005, inf=1e9;
ll n, sp[20][maxn];
ll L[20][maxn], R[20][maxn], Max[20][maxn];

void init(ll N, vector<ll> H) 
{
    n=N, H.insert(H.begin(), inf), H.insert(H.end(), inf);
    for (ll i=0; i<=n+1; i++) sp[0][i]=H[i];
    for (ll i=1; i<20; i++)
        for (ll j=0; j+(1<<i)<=n+2; j++)
            sp[i][j]=max(sp[i-1][j], sp[i-1][j+(1<<i-1)]);
    stack <ll> st; st.push(0), L[0][0]=0;
    for (ll i=1; i<=n+1; i++)
    {
        while (H[st.top()]<H[i]) st.pop();
        L[0][i]=st.top(), st.push(i);
    }
    while (sz(st)) st.pop(); st.push(n+1), R[0][n+1]=n+1;
    for (ll i=n; i>=0; i--)
    {
        while (H[st.top()]<H[i]) st.pop();
        R[0][i]=st.top(), st.push(i);
    }
    for (ll i=0; i<=n+1; i++)
        Max[0][i]=H[L[0][i]]>H[R[0][i]]?L[0][i]:R[0][i];
    for (ll i=1; i<20; i++)
        for (ll j=0; j<=n+1; j++)
        {
            L[i][j]=L[i-1][L[i-1][j]];
            R[i][j]=R[i-1][R[i-1][j]];
            Max[i][j]=Max[i-1][Max[i-1][j]];
        }
}

ll query(ll l, ll r)
{
    ll j=__lg(r-l+1);
    return max(sp[j][l], sp[j][r-(1<<j)+1]);
}

bool check(ll i, ll l, ll r) {return query(i, r)==query(l, r);}

int minimum_jumps(int A, int B, int C, int D) 
{
    A++, B++, C++, D++;
    if (!check(B, C, D)) return -1;
    for (ll i=19; i>=0; i--)
        if (check(L[i][B], C, D) && L[i][B]>=A)
            B=L[i][B];
    ll ans=0;
    for (ll i=19; i>=0; i--)
        if (Max[i][B]<C && R[0][Max[i][B]]<=C && check(Max[i][B], C, D))
            ans+=1<<i, B=Max[i][B];
    if (R[0][B]>=C) return ans+1;
    if (check(Max[0][B], C, D)) B=Max[0][B], ans++;
    for (ll i=19; i>=0; i--)
        if (R[i][B]<C)
            ans+=1<<i, B=R[i][B];
    return ans+1;
}

Compilation message (stderr)

jumps.cpp: In function 'void init(int, std::vector<int>)':
jumps.cpp:24:53: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   24 |             sp[i][j]=max(sp[i-1][j], sp[i-1][j+(1<<i-1)]);
      |                                                    ~^~
jumps.cpp:31:5: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
   31 |     while (sz(st)) st.pop(); st.push(n+1), R[0][n+1]=n+1;
      |     ^~~~~
jumps.cpp:31:30: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'while'
   31 |     while (sz(st)) st.pop(); st.push(n+1), R[0][n+1]=n+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