#include <bits/stdc++.h>
using namespace std;
using ll = long long; using pii = pair<ll,ll>;
const ll INF = 1e18;
//#include "books.h"
ll minimum_walk(vector<int> p, int s) {
ll N = p.size();
ll flux[N];
for (ll i=0;i<N;i++) {
flux[i]=0;
}
ll invcnt=0;
for (ll i=0;i<N;i++) {
if (p[i]>i) {
invcnt++;
flux[i]++;
flux[p[i]]--;
}
}
if (invcnt==0) {
return 0;
}
ll pf[N+1];
pf[0]=0;
ll ans = 0;
for (ll i=0;i<N;i++) {
pf[i+1]=pf[i]+flux[i];
//cout << "x="<<(i+1)<<", pf[x]="<<pf[i+1]<<"\n";
if (pf[i+1]>1) {
ans += 2*(pf[i+1]-1);
}
}
ll maxl[N+1]; ll minl[N+1];
for (ll i=0;i<=N;i++) {
maxl[i]=-INF;
minl[i]=INF;
}
for (ll i=1;i<=N;i++) {
maxl[pf[i]]=max(maxl[pf[i]],i);
minl[pf[i]]=min(minl[pf[i]],i-1);
}
for (ll i=N;i>=1;i--) {
maxl[i-1]=max(maxl[i],maxl[i-1]);
minl[i-1]=min(minl[i],minl[i-1]);
}
if (minl[1]!=INF) { //below valid if s=0
ans += 2*(maxl[1]-minl[1]);
}
if (minl[1]!=INF) { //below valid if s=0
if (s==0) {
//ans += 2*(minl[1]);
}
}
if (s!=0) {
bool found[N];
ll grp[N];
bool grpf[N];
vector<vector<ll>> gelem;
bool foundg[N];
bool found2[N];
for (ll i=0;i<N;i++) {
found[i]=0;
grp[i]=-1;
grpf[i]=0;
foundg[i]=0;
found2[i]=0;
}
for (ll i=0;i<N;i++) {
if (!found[i]) {
vector<ll> enew;
//cout << "f1\n";
ll j = i;
ll T = 0;
ll lp=INF; ll rp=-INF;
do {
T++;
lp = min(lp,j);
rp = max(rp,j);
found[j]=1;
enew.push_back(j);
j=p[j];
} while (j != i);
for (ll x: enew) {
grp[x]=gelem.size();
//cout << "x="<<x<<", grp[x]="<<grp[x]<<"\n";
}
gelem.push_back(enew);
}
}
priority_queue<pii> pq; //{-time,position}
pq.push({0,s});
ll Tmin = INF;
while (!pq.empty()) {
auto A = pq.top(); pq.pop();
ll t = -A.first; ll x = A.second;
if (found2[x]) {
continue;
}
found2[x]=1;
if (x==maxl[1] || x==minl[1]) {
Tmin = min(Tmin,t);
}
ll g = grp[x];
if (!foundg[g]) {
foundg[g]=1;
ll ymin = INF; ll ymax = -INF;
for (ll y: gelem[g]) {
ymin = min(ymin,y);
ymax = max(ymax,y);
}
for (ll z=ymin;z<=ymax;z++) {
pq.push({-t,z});
}
}
if (x>0) {
pq.push({-t-1,x-1});
}
if (x<(N-1)) {
pq.push({-t-1,x+1});
}
}
ans += 2*Tmin;
}
//cout << "minl[1],maxl[1]="<<minl[1]<<","<<maxl[1]<<"\n";
return ans;
}
/*int main() {
vector<int> p1 = {0,1,4,3,2,5,6};
cout << minimum_walk(p1,3);
}*/
Compilation message
books.cpp: In function 'll minimum_walk(std::vector<int>, int)':
books.cpp:59:8: warning: variable 'grpf' set but not used [-Wunused-but-set-variable]
59 | bool grpf[N];
| ^~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
344 KB |
3rd lines differ - on the 1st token, expected: '6', found: '4' |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
344 KB |
3rd lines differ - on the 1st token, expected: '6', found: '4' |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
344 KB |
3rd lines differ - on the 1st token, expected: '6', found: '4' |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
344 KB |
Output is correct |
| 2 |
Correct |
1 ms |
604 KB |
Output is correct |
| 3 |
Correct |
1 ms |
348 KB |
Output is correct |
| 4 |
Incorrect |
0 ms |
348 KB |
3rd lines differ - on the 1st token, expected: '2094', found: '2596' |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
344 KB |
3rd lines differ - on the 1st token, expected: '6', found: '4' |
| 2 |
Halted |
0 ms |
0 KB |
- |
