#include<bits/stdc++.h>
using namespace std;
#define ii pair <int, int>
#define app push_back
#define all(a) a.begin(), a.end()
#define bp __builtin_popcountll
#define ll long long
#define mp make_pair
#define f first
#define s second
#define Time (double)clock()/CLOCKS_PER_SEC
const int N = 1e5+7, INF = 1e9+7;
int n, k, q;
int a[N], ans[N];
int pref[N], suff[N];
int newl[N], newr[N];
vector <int> pos[N];
int par[N];
int root(int u) {
if (par[u] == u)
return u;
else
return par[u] = root(par[u]);
}
void merge(int u, int v) {
u = root(u);
v = root(v);
if (u != v) {
par[u] = v;
}
}
int link_l[N], link_r[N];
signed main() {
#ifdef HOME
freopen("input.txt", "r", stdin);
#else
#define endl '\n'
ios_base::sync_with_stdio(0); cin.tie(0);
#endif
cin >> n >> k >> q;
for (int i = 1; i <= n; ++i)
cin >> a[i];
vector <ii> d;
for (int i = 0; i < q; ++i) {
int u, v;
cin >> u >> v;
if (v < u)
swap(u, v);
d.app(mp(u, v));
ans[i] = INF;
}
for (int i = 1; i <= k; ++i)
pos[i].app(0);
for (int i = 1; i <= n; ++i)
pos[a[i]].app(i);
for (int i = 1; i <= k; ++i)
pos[i].app(n+1);
for (int i = 1; i <= n; ++i)
par[i] = i;
auto same_dist = [&](int i, int j) {
int p1 = lower_bound(all(pos[a[i]]), i) - pos[a[i]].begin();
int p2 = lower_bound(all(pos[a[j]]), j) - pos[a[j]].begin();
return abs(p1-p2);
};
for (int x = 1; x <= k; ++x) {
//cout << "x " << x << endl;
for (int i : pos[x]) {
if (i && a[i - 1] <= x) {
merge(i, i - 1);
}
if (i + 1 <= n && a[i + 1] <= x) {
merge(i, i + 1);
}
}
memset(link_l, 0, sizeof link_l);
memset(link_r, 0, sizeof link_r);
for (int i = 1; i <= n; ++i)
newl[i] = newr[i] = INF;
for (int i : pos[x]) {
link_l[i] = link_r[i] = i;
newl[i] = newr[i] = 0;
for (int j = i - 1; j; --j) {
if (a[j] >= a[i])
break;
newr[j] = suff[j]+1;
link_r[j] = i;
}
for (int j = i + 1; j <= n; ++j) {
if (a[j] >= a[i])
break;
newl[j] = pref[j]+1;
link_l[j] = i;
}
}
for (int i = 1; i <= n; ++i) {
newl[i] = min(newl[i], newr[i]+1);
newr[i] = min(newr[i], newl[i]+1);
}
//pref - dist to nearest prefix maximum
//suff - dist to nearest suffix maximum
//newl - dist to nearest left x
//newr - dist to nearest right x
//link_l = number of the nearest left x
int lf = 0;
for (int i = 1; i <= n; ++i) {
if (a[i] > x) {
lf = i;
continue;
}
auto t = upper_bound(all(pos[x]), lf);
if (*t <= i) {
auto link = prev(upper_bound(all(pos[x]), i));
pref[i] = newl[i] + (link - t);
}
else if (link_r[i]) {
pref[i] = min(pref[i], newr[i]);
}
}
int rf = n+1;
for (int i = n; i; --i) {
if (a[i] > x) {
rf = i;
continue;
}
auto t = prev(upper_bound(all(pos[x]), rf));
if (*t >= i) {
auto link = lower_bound(all(pos[x]), i);
suff[i] = newr[i] + (t - link);
}
else if (link_l[i]) {
suff[i] = min(suff[i], newl[i]);
}
}
for (int i = 0; i < q; ++i) {
int u = d[i].f, v = d[i].s;
if (root(u) == root(v) && ans[i] == INF) {
if (link_l[u] && link_l[v]) {
ans[i] = min(ans[i], newl[u] + newl[v] + same_dist(link_l[u], link_l[v]));
}
if (link_l[u] && link_r[v]) {
ans[i] = min(ans[i], newl[u] + newr[v] + same_dist(link_l[u], link_r[v]));
}
if (link_r[u] && link_l[v]) {
ans[i] = min(ans[i], newr[u] + newl[v] + same_dist(link_r[u], link_l[v]));
}
if (link_r[u] && link_r[v]) {
ans[i] = min(ans[i], newr[u] + newr[v] + same_dist(link_r[u], link_r[v]));
}
}
}
}
for (int i = 0; i < q; ++i)
cout << ans[i] - 1 << endl;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
9 ms |
3584 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
40 ms |
3584 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
218 ms |
9456 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
2086 ms |
12312 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
