Submission #1062960

#	Time	Username	Problem	Language	Result	Execution time	Memory
1062960		vjudge1	Rainforest Jumps (APIO21_jumps)	C++17	0 / 100	4017 ms	31984 KiB

jumps

#include <bits/stdc++.h>
#define all(x) (x).begin(),(x).end()
using namespace std;

using ll = long long;
using ld = long double;

//#define int ll
#define sz(x) ((int)(x).size())

using pii = pair<int,int>;
using tii = tuple<int,int,int>;

const int nmax = 2e5 + 5;
int toright[nmax][18], toleft[nmax][18];

int N;

void init(int N_, std::vector<int> H) {
   N = N_;
   vector<int> st;
   H.emplace_back(1e9 + 5);
   st.emplace_back(N);
   toleft[N][0] = N;
   for(int i = 0; i < N; i++) {
      while(H[st.back()] < H[i]) st.pop_back();
      toleft[i][0] = st.back();
      st.emplace_back(i);
   }
   for(int step = 1; step < 18; step++) for(int i = 0; i <= N; i++) toleft[i][step] = toleft[toleft[i][step - 1]][step - 1];
   
   st.clear();
   st.emplace_back(N);
   for(int i = N - 1; i >= 0; i--) {
      while(H[st.back()] < H[i]) st.pop_back();
      toright[i][0] = st.back();
      st.emplace_back(i);
   }
   toright[N][0] = N;
   for(int step = 1; step < 18; step++) for(int i = 0; i <= N; i++) toright[i][step] = toright[toright[i][step - 1]][step - 1];
}

int leftist(int B, int C, int D) {
   int cnt = 0;
   for(int i = 17; i >= 0; i--) {
      int cand = toright[B][i];
      if(cand >= C) continue;
      B = cand;
      cnt += (1 << i);
   }
   if(toright[B][0] > D) return -1;
   return cnt + 1;
}

int minimum_jumps(int A, int B, int C, int D) {
   int sol = -1;
   for(int i = A; i <= B; i++) {
      int r = leftist(i, C, D);
      if(r != -1) sol = (sol == -1? r : min(sol, r));
   }
   return sol;
   //for(int i = 17; i >= 0; i--) {
      //int cand = toleft[B][i];
      //if(cand == N) continue;
      //if(cand < A) continue;
      //if(toright[cand][0] > D) continue;
      //if(toright[cand][0] >= C) return 1;
      //B = cand;
   //} 
   
   
}


/**
      Töte es durch genaue Untersuchung\Töte es kann es nur noch schlimmer machen\Es lässt es irgendwie atmen
--
*/ 

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