| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 121991 | nvmdava | Ancient Books (IOI17_books) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include "books.h"
#include <bits/stdc++.h>
using namespace std;
bool in[1000005];
vector<pair<int, int> > cyc, tmp;
int mn, mx;
long long res;
void dfs(int i, vector<int>& p){
if(in[i]) return;
in[i] = 1;
mx = max(mx, i);
mn = min(mn, i);
dfs(p[i], p);
}
long long minimum_walk(std::vector<int> p, int s) {
for(int i = 0; i < p.size(); i++){
res += abs(p[i] - i);
if(in[i]) continue;
mn = i;
mx = i;
dfs(i, p);
if(mn != mx)tmp.push_back({mn , mx});
}
if(tmp.empty()) return 0;
sort(tmp.begin(), tmp.end());
mx = -1;
bool in = 0;
for(auto& x : tmp){
if(mx < x.first){
if(!cyc.empty()){
res += 2 * (x.first - mx);
}
cyc.push_back(x);
}
if(s >= x.first && s <= x.second) in = 1;
mx = max(mx, x.second);
}
if(s < cyc[0].first) res += 2 * (cyc[0].first - s);
else if(s > cyc.back().second) res += 2 * (s - cyc.back().second);
else if(in == 0){
int l = s, r = s;
while(l >= 0 && in[l] == 0) l--;
while(r != p.size() && in[r] == 0) r++;
if(l == -1) res += (r - s) * 2;
else if(r == p.size()) res += (s - l) * 2;
else {
res += min(s - l, r - s) * 2;
}
}
return res;
}