Submission #1035367

#	Time	Username	Problem	Language	Result	Execution time	Memory
1035367		AverageAmogusEnjoyer	Rainforest Jumps (APIO21_jumps)	C++17	8 / 100	4065 ms	21708 KiB

jumps

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
template<class T> bool cmin(T &i, T j) { return i > j ? i=j,true:false; }
template<class T> bool cmax(T &i, T j) { return i < j ? i=j,true:false; }

mt19937 mrand(chrono::steady_clock::now().time_since_epoch().count());

int rng() {
    return abs((int)mrand());
}

// Current challenge: finish CSES problemset!!

constexpr int nax = 200200, lg = 20;
int h[nax];
int par[nax][2];
int partree[nax];
int sparse[lg][nax];

void init(int n, vector<int> H) {
    for (int i=0;i<n;i++) {
        h[i] = H[i]-1;
        par[i][0] = par[i][1] = n;
    }
    for (int i=0;i<n;i++) {
        sparse[0][i] = h[i];
    }
    for (int pw=1;pw<lg;pw++) {
        for (int i=0;i<n;i++) {
            sparse[pw][i] = max(sparse[pw-1][i],sparse[pw-1][min(n-1,i+(1<<(pw-1)))]);
        }
    }
    h[n] = n;
    vector<int> stk;
    for (int i=0;i<n;i++) {
        while(!stk.empty() && h[stk.back()] < h[i]) { stk.pop_back(); } 
        if (!stk.empty()) par[i][0] = stk.back();
        stk.push_back(i);
    }
    stk.clear();
    for (int i=n-1;i>=0;i--) {
        while(!stk.empty() && h[stk.back()] < h[i]) { stk.pop_back(); } 
        if (!stk.empty()) par[i][1] = stk.back();
        stk.push_back(i);
    }
    for (int i=0;i<n;i++) {
        if (h[i] == n-1) { partree[i] = -1; continue; } 
        assert(h[par[i][0]] != h[par[i][1]]);
        if (par[i][0] == n) {
            partree[i] = par[i][1];
        } else if (par[i][1] == n) {
            partree[i] = par[i][0];
        } else {
            partree[i] = (h[par[i][0]] > h[par[i][1]] ? par[i][0] : par[i][1]);
        }
    }       
}

int jump(int a,int b) {
    if (h[a] > h[b]) { return nax; } 
    int x = a;
    int ans = 0;
    // int cnt_not_greatest = 0;
    int w = -1;
    assert(a!=b);
    int bit = 31 - __builtin_clz(b-a+1);
    if (max(sparse[bit][a],sparse[bit][b-(1<<bit)+1]) > h[b]) {
        return nax;
    }
    while(x != b) {
        if (h[par[x][0]] > h[b]) {
            // cnt_not_greatest++;
            x = par[x][1];
            assert(w != 0);
            w = 1;
            ans++;
        } else if (h[par[x][1]] > h[b]) {
            x = par[x][0];
            assert(w != 1);
            w = 0;
            // cnt_not_greatest++;
            ans++;
        } else {
            x = (h[par[x][0]] > h[par[x][1]] ? par[x][0] : par[x][1]);
            ans++;
        }
    }
    // assert(cnt_not_greatest<=1);
    return ans;
}

int minimum_jumps(int a,int b,int c,int d) {
    int ans = nax;
    for (int A=a;A<=b;A++) {
        for (int C=c;C<=d;C++) {
            cmin(ans,jump(A,C));
        }
    }
    return (ans == nax ? -1 : ans);
}

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