#include "jumps.h"
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define sz(a) (int)(a.size())
typedef long long int ll;
typedef pair<int,int> pii;
typedef vector<vector<int>> vii;
const int MAXN = 2e5+5;
int l[20][MAXN],r[20][MAXN],high[20][MAXN];
vector<int>H;
void init(int n, vector<int>h){
H = h;
H.insert(H.begin(),0);
h.pb(1e9);
stack<pii>stk;
for(int i=0;i<=n+1;i++){
while(!stk.empty() && stk.top().fi < h[i])stk.pop();
if(!stk.empty())l[0][i] = stk.top().se;
else l[0][i] = i;
stk.push({h[i],i});
}
while(!stk.empty())stk.pop();
for(int i=n+1;i>=0;i--){
while(!stk.empty() && stk.top().fi < h[i])stk.pop();
if(!stk.empty())r[0][i] = stk.top().se;
else r[0][i] = i;
stk.push({h[i],i});
}
for(int i=0;i<=n+1;i++){
high[0][i] = (H[r[0][i]] > H[l[0][i]])?r[0][i]:l[0][i];
}
for(int j=1;j<20;j++){
for(int i=0;i<=n+1;i++){
l[j][i] = l[j-1][l[j-1][i]];
r[j][i] = r[j-1][r[j-1][i]];
high[j][i] = high[j-1][high[j-1][i]];
}
}
}
//
int minimum_jumps(int a,int b,int c,int d){
a++;
b++;
c++;
d++;
if(c == b+1){
if(r[0][b] > d)return -1;
return 1;
}
int mid = b+1;
for(int j=19;j>=0;j--){
if(r[j][mid] < c){
mid = r[j][mid];
}
}
if(H[b] > H[mid])return r[0][b]<=d?1:-1;
//anything higher this mid point can be possibly "unreachable"
//otherwise we are safe to use high edges
int cur = b;
for(int j=19;j>=0;j--){
if(l[j][cur] >= a && H[l[j][cur]] < H[mid])cur = l[j][cur];
}
//we want to start at cur
int ans = 0;
if(l[0][cur] >= a){
if(r[0][l[0][cur]] <= d)return 1;
}else{
//if l[0][cur] reachable we take it,else we can never go left again
for(int j=19;j>=0;j--){
if(H[high[j][cur]] <= H[mid]){
ans+=(1<<j);
cur = high[j][cur];
}
}
if(cur == mid){
if(r[0][mid] <= d)return ans+1;
else return -1;
}else{
//since we cant jump right without >= h[mid]
//we check if jumping left is reachable
if(l[0][cur] && r[0][l[0][cur]] <= d)return ans+2;
}
}
//we cant jump to the left anymore : (
for(int j=19;j>=0;j--){
if(r[j][cur] < c){
cur = r[j][cur];
ans+=(1<<j);
}
}
if(r[0][cur] <= d && r[0][cur] >= c)return ans+1;
else return -1;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
584 KB |
Output is correct |
| 2 |
Correct |
1 ms |
584 KB |
Output is correct |
| 3 |
Incorrect |
197 ms |
40976 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
584 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
584 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
584 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
584 KB |
Output is correct |
| 2 |
Incorrect |
1 ms |
584 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
584 KB |
Output is correct |
| 2 |
Incorrect |
1 ms |
584 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
584 KB |
Output is correct |
| 2 |
Correct |
1 ms |
584 KB |
Output is correct |
| 3 |
Incorrect |
197 ms |
40976 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
