Submission #1162483

#	Time	Username	Problem	Language	Result	Execution time	Memory
1162483		tw20000807	Rainforest Jumps (APIO21_jumps)	C++20	21 / 100	541 ms	1114112 KiB

jumps

#include<bits/stdc++.h>

#define ll long long
#define all(v) v.begin(), v.end()
#define SZ(x) (int)x.size()
#define pii pair<int, int>
#define X first
#define Y second

using namespace std;

struct TABLE{
    int n;
    int g;
    vector< vector< int > > dp;
    TABLE(){}
    TABLE(vector< int > &v){
        n = SZ(v);
        g = __lg(n) + 1;
        dp.resize(g, vector< int >(n));
        for(int i = 0; i < n; ++i){
            dp[0][i] = v[i];
        }
        for(int j = 1; j < g; ++j){
            for(int i = 0; i + (1 << j) - 1 < n; ++i){
                dp[j][i] = min(dp[j - 1][i], dp[j - 1][i + (1 << (j - 1))]);
            }
        }
    }
    int query(int l, int r){
        int lg = __lg(r - l + 1);
        return min(dp[lg][l], dp[lg][r - (1 << lg) + 1]);
    }
};

vector< TABLE > mn;
vector< vector< int > > dis;
void init(int n, vector<int> h) {
    vector< int > l(n, -1), r(n, -1);
    {
        vector< int > stk;
        for(int i = 0; i < n; ++i){
            while(!stk.empty() && h[stk.back()] < h[i]){
                r[stk.back()] = i;
                stk.pop_back();
            }
            l[i] = stk.empty() ? -1 : stk.back();
            stk.push_back(i);
        }
    }
    // for(int i = 0; i < n; ++i) cerr << l[i] << " " << r[i] << "--\n";
    auto f = [&](vector< int > &dis, int s) -> void {
        vector< int > dq{s};
        dis[s] = 0;
        dq.push_back(s);
        int id = 0;
        while(id < SZ(dq)){
            int cur = dq[id++];
            for(auto nxt : {l[cur], r[cur]}) if(nxt != -1) {
                if(dis[nxt] > dis[cur] + 1){
                    dis[nxt] = dis[cur] + 1;
                    dq.push_back(nxt);
                }
            }
        }
    };
    dis.resize(n, vector< int >(n, 1e9));
    mn.resize(n);
    for(int i = 0; i < n; ++i){
        f(dis[i], i);
        mn[i] = TABLE(dis[i]);
    }
}

int minimum_jumps(int a, int b, int c, int d) {
    int ans = 1e9;
    for(int i = a; i <= b; ++i){
        ans = min(ans, mn[i].query(c, d));
    }
    if(ans == 1e9) return -1;
    else return ans;
}

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