Submission #931802

#	Time	Username	Problem	Language	Result	Execution time	Memory
931802		Arp	Rainforest Jumps (APIO21_jumps)	C++17	33 / 100	4067 ms	63056 KiB

jumps

#include<bits/stdc++.h>
using namespace std;
 
const int N = 2e5+10;
const int K = 18;
const int INF = 1e9;
 
int up[K][N], mvr[K][N], mvl[K][N], h[N], idx[N], lh[N], rh[N], n;
int sp[K][N], lg[N];
 
int que(int l, int r) {
    int i=lg[r-l+1];
    return max(sp[i][l], sp[i][r-(1<<i)+1]);
}
 
void init(int N, std::vector<int> H) {
    n=N;
    for (int i=0; i<n; ++i) h[i+1]=H[i], idx[h[i+1]]=i+1;
 
    h[0]=INF-1, h[n+1]=INF;
    stack<int> st; st.push(0);
 
    for (int i=1; i<=n; ++i) {
        while (h[st.top()] <= h[i]) st.pop();
        assert(!st.empty());
        lh[i]=st.top(), st.push(i);
    } st=stack<int>();
 
    for (int i=1; i<=n; ++i) sp[0][i]=h[i];
    for (int j=1; j<K; ++j) {
        for (int i=1; i+(1<<(j-1))<=n; ++i) sp[j][i]=max(sp[j-1][i], sp[j-1][i+(1<<(j-1))]);
    }
 
    lg[1]=0;
    for (int i=2; i<N; ++i) lg[i]=lg[i/2]+1;
 
    st.push(n+1);
    for (int i=n; i>=1; --i) {
        while (h[st.top()] <= h[i]) st.pop();
        assert(!st.empty());
        rh[i]=st.top(), st.push(i);
    }
 
    // assume A=B, C=D for testing reasons
    for (int i=n; i>=1; --i) {
        int j=idx[i];
 
        int r=rh[j], l=lh[j];
        assert(h[l] > h[j] && h[j] < h[r]);
 
        if (h[l] > h[r]) up[0][j]=l;
        else up[0][j]=r;
 
        for (int k=1; k<K; ++k) up[k][j]=up[k-1][up[k-1][j]];
    }
 
    for (int k=0; k<K; ++k) mvr[k][n+1]=n+1;
 
    for (int i=n; i>=1; --i) {
        int j=idx[i];
        mvr[0][j]=rh[j];
        for (int k=1; k<K; ++k) mvr[k][j]=mvr[k-1][mvr[k-1][j]];
    }
 
    for (int i=n; i>=1; --i) {
        int j=idx[i];
        mvl[0][j]=lh[j];
        for (int k=1; k<K; ++k) mvl[k][j]=mvl[k-1][mvl[k-1][j]];
    }
}

int minimum_jumps(int a,int b,int c,int d){
  a ++,b ++;
  c ++,d ++;
  // if(one) return c - b;  
  int m2 = c;
  int mxv = que(c,d);
  for(int i = c + 1;i <= d;i ++){
    if(h[i] > h[m2]) m2 = i;
  }
  int m1 = -1;
  for(int i = b;i >= a;i--){
    if(h[i] > h[m2]){
		break;
    }else if(m1 == -1){
      m1 = i;
    }else if(h[i] > h[m1]){
      m1 = i;
    } 
  }
  if(m1 == -1) return -1;
  int x = m1;
  int ans = 0;
  while (true) {
        int u=up[0][x];
        // if (u < c && rh[u] < c && h[u] < mxv) x=u, ans+=(1<<j);
      if(u < c && rh[x] < c && h[u] < h[m2]){
          x = u;
          ans +=1;
        }else{
          break;
        }
    }
 
    // if (up[0][x] < c && h[up[0][x]] < mxv && rh[x] < c) x=up[0][x], ++ans;
 
    while(true) {
        int u=rh[x];
         if (u < c) x=u, ans+=1;
         else break;
    }
     if (rh[x] >= c && rh[x] <= d) return ans+1;
  return -1;
}

Compilation message (stderr)

jumps.cpp: In function 'int minimum_jumps(int, int, int, int)':
jumps.cpp:77:7: warning: unused variable 'mxv' [-Wunused-variable]
   77 |   int mxv = que(c,d);
      |       ^~~

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