Submission #569279

#	Time	Username	Problem	Language	Result	Execution time	Memory
569279		SmolBrain	Rainforest Jumps (APIO21_jumps)	C++17	23 / 100	1315 ms	58088 KiB

jumps

// Om Namah Shivaya
// Master in 16 days

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define endl '\n'
#define pb push_back
#define conts continue
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
#define ff first
#define ss second
#define ceil2(x,y) ((x+y-1) / (y))
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#ifndef ONLINE_JUDGE
#define debug(x) cout << #x <<" = "; print(x); cout << endl
#else
#define debug(x)
#endif

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

bool iseven(ll n) {if ((n & 1) == 0) return true; return false;}

void print(ll t) {cout << t;}
void print(int t) {cout << t;}
void print(string t) {cout << t;}
void print(char t) {cout << t;}
void print(double t) {cout << t;}
void print(ld t) {cout << t;}

template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(pair <T, V> p) {cout << "{"; print(p.ff); cout << ","; print(p.ss); cout << "}";}
template <class T> void print(vector <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(set <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(multiset <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T, class V> void print(map <T, V> v) {cout << "[ "; for (auto i : v) {print(i); cout << " ";} cout << "]";}
template<typename T> void amin(T &a, T b) { a = min(a, b); }
template<typename T> void amax(T &a, T b) { a = max(a, b); }

void usaco(string filename) {
    freopen((filename + ".in").c_str(), "r", stdin);
    freopen((filename + ".out").c_str(), "w", stdout);
}

const int MOD = 1e9 + 7;
const int maxn = 2e5 + 5;
const int inf1 = 1e9 + 5;
const ll inf2 = ll(1e18) + 5;

// editorial approach

const int LOG = 18;

vector<int> adj[maxn];
vector<vector<int>> up1(maxn, vector<int>(LOG, -1));
vector<vector<int>> up2(maxn, vector<int>(LOG, -1));
int n;
vector<int> h;

void init(int on, vector<int> oh) {
    n = on;
    h = oh;

    stack<int> st;
    vector<int> ngeright(n, -1), ngeleft(n, -1);

    rep(i, n) {
        while (!st.empty() and h[i] > h[st.top()]) {
            ngeright[st.top()] = i;
            st.pop();
        }

        st.push(i);
    }

    while (!st.empty()) st.pop();

    rev(i, n - 1, 0) {
        while (!st.empty() and h[i] > h[st.top()]) {
            ngeleft[st.top()] = i;
            st.pop();
        }

        st.push(i);
    }

    while (!st.empty()) st.pop();

    rep(i, n) {
        if (ngeleft[i] != -1) {
            adj[i].pb(ngeleft[i]);
        }

        if (ngeright[i] != -1) {
            adj[i].pb(ngeright[i]);
        }
    }

    rep(i, n) sort(all(adj[i]));

    vector<pii> b;
    rep(i, n) b.pb({h[i], i});

    sort(rall(b));

    trav(p, b) {
        int i = p.ss;

        if (adj[i].empty()) conts;
        int small = adj[i][0];
        int big = -1;
        if (sz(adj[i]) >= 2) big = adj[i][1];

        if (big != -1) {
            if (h[big] < h[small]) {
                swap(big, small);
            }
        }

        if (big != -1) {
            up1[i][0] = big;
            rep1(j, LOG - 1) {
                int nxt = up1[i][j - 1];
                if (nxt != -1) {
                    up1[i][j] = up1[nxt][j - 1];
                }
            }
        }

        up2[i][0] = small;
        rep1(j, LOG - 1) {
            int nxt = up2[i][j - 1];
            if (nxt != -1) {
                up2[i][j] = up2[nxt][j - 1];
            }
        }
    }
}

int minimum_jumps(int a, int b, int c, int d) {
    int moves = 0;
    int node = a;

    rev(j, LOG - 1, 0) {
        int nxt = up1[node][j];
        if (nxt == -1 or h[nxt] > h[c]) {
            conts;
        }

        node = up1[node][j];
        moves += (1 << j);
    }

    rev(j, LOG - 1, 0) {
        int nxt = up2[node][j];
        if (nxt == -1 or h[nxt] > h[c]) {
            conts;
        }

        node = up2[node][j];
        moves += (1 << j);
    }

    if (node == c) return moves;
    else return -1;
    
    // queue<int> q;
    // vector<bool> vis(n);
    // vector<int> dis(n);

    // for (int i = a; i <= b; ++i) {
    //     q.push(i);
    //     vis[i] = 1;
    //     dis[i] = 0;
    // }

    // while (!q.empty()) {
    //     int node = q.front();
    //     q.pop();

    //     if (node >= c and node <= d) {
    //         return dis[node];
    //     }

    //     trav(child, adj[node]) {
    //         if (vis[child]) conts;

    //         q.push(child);
    //         vis[child] = 1;
    //         dis[child] = dis[node] + 1;
    //     }
    // }

    // return -1;
}

Compilation message (stderr)

jumps.cpp: In function 'void usaco(std::string)':
jumps.cpp:64:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |     freopen((filename + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
jumps.cpp:65:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |     freopen((filename + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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