Submission #1252147

#	Time	Username	Problem	Language	Result	Execution time	Memory
1252147		FernandoJC07	Obstacles for a Llama (IOI25_obstacles)	C++20	24 / 100	116 ms	10944 KiB

obstacles

#include <bits/stdc++.h>
#define For(i, a, n) for(int i = a; i<n; ++i)
#define vi vector<int>
#define vii vector<vector<int>>
using namespace std;

vi res;

void initialize(vi T, vi H){
    int n = T.size();
    int m = H.size();
    vi mh(m); mh[0] = H[0];
    For(i, 1, m) mh[i] = min(mh[i-1], H[i]);
    reverse(mh.begin(), mh.end());
    vi lt(n);
    For(i, 0, n){
        int lower = m-1 - (lower_bound(mh.begin(), mh.end(), T[i]) - mh.begin());
        lt[i] = lower;
    }
    vi maxlt(n); maxlt[0] = lt[0];
    For(i, 1, n) maxlt[i] = max(maxlt[i-1], lt[i]);
    vi mt(n); mt[0] = T[0]; For(i, 1, n) mt[i] = max(mt[i-1], T[i]);
    For(i, 0, m){
        int upper = upper_bound(mt.begin(), mt.end(), H[i]) - mt.begin();
        --upper;
        if(upper==-1) continue;
        if(maxlt[upper]>=i || upper == n-1) res.push_back(i);
    }
}

bool can_reach(int L, int R, int S, int D){
    if(S>D) swap(S, D);
    auto i1 = lower_bound(res.begin(), res.end(), S);
    auto i2 = upper_bound(res.begin(), res.end(), D);
    return (i1 == i2);
}

• Subtask 0: 0 / 0
• Subtask 1: 10 / 10
• Subtask 2: 14 / 14
• Subtask 3: 0 / 13
• Subtask 4: 0 / 21
• Subtask 5: 0 / 25
• Subtask 6: 0 / 17