Submission #750604

#	Time	Username	Problem	Language	Result	Execution time	Memory
750604		snpmrnhlol	Rainforest Jumps (APIO21_jumps)	C++17	48 / 100	1313 ms	50504 KiB

jumps

#include "jumps.h"
#include <bits/stdc++.h>
using namespace std;
const int N = 2e5;
const int K = 20;
int v[N + 2];
int l[N + 2][K];
int r[N + 2][K];
int p[N + 2][K];
stack <int> stk;
int en;
void init(int n, std::vector<int> H) {
    int i,j;en = n;
    for(i = 1;i <= n;i++){
        v[i] = H[i - 1];
    }
    r[n + 1][0] = n + 1;
    l[0][0] = 0;
    for(i = 1;i <= n;i++){
        while(!stk.empty() && v[stk.top()] < v[i]){
            r[stk.top()][0] = i;stk.pop();
        }
        stk.push(i);
    }
    while(!stk.empty()){
        r[stk.top()][0] = n + 1;
        stk.pop();
    }
    for(i = n;i >= 1;i--){
        while(!stk.empty() && v[stk.top()] < v[i]){
            l[stk.top()][0] = i;stk.pop();
        }
        stk.push(i);
    }
    while(!stk.empty()){
        l[stk.top()][0] = 0;
        stk.pop();
    }
    v[0] = v[n + 1] = -2e9;
    for(i = 0;i <= n + 1;i++){
        if(v[l[i][0]] > v[r[i][0]]){
            p[i][0] = l[i][0];
        }else p[i][0] = r[i][0];
    }
    for(j = 1;j <= 19;j++){
        for(i = 0;i <= n + 1;i++){
            if(i > 0 && i < n + 1)p[i][j] = p[p[i][j - 1]][j - 1];
            l[i][j] = l[l[i][j - 1]][j - 1];
            r[i][j] = r[r[i][j - 1]][j - 1];
        }
    }
    /*for(j = 0;j <= 19;j++){
        for(i = 0;i <= n + 1;i++){
            cout<<p[i][j]<<' '<<r[i][j]<<' '<<l[i][j]<<'\n';
        }
    }*/
}

int minimum_jumps(int a, int b, int c, int d){
    a++;b++;c++;d++;
    int x = b,i,r2 = 0;
    int n = en;
    for(i = 19;i >= 0;i--){
        if(l[x][i] >= a && r[l[x][i]][0] <= d){
            x = l[x][i];
        }
    }
    //cout<<x<<'\n';
    for(i = 19;i >= 0;i--){
        if(1 <= p[x][i] && p[x][i] <= n && p[x][i] < c && r[p[x][i]][0] <= d){
            r2+=(1<<i);
            x = p[x][i];
        }
    }
    //cout<<x<<'\n';
    for(i = 19;i >= 0;i--){
        if(r[x][i] < c){
            x = r[x][i];
            r2+=(1<<i);
        }
    }
    //cout<<x<<'\n';
    if(x < c){
        x = r[x][0];
        r2++;
    }
    //cout<<x<<'\n';
    if(c <= x && x <= d)return r2;
    return -1;
}
/**
7 3
3 2 1 6 4 5 7
4 4 6 6
1 3 5 6
0 1 2 2
**/

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