#include "walk.h"
#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>
#include <queue>
#include <stack>
#include <map>
typedef long long llong;
const int MAXN = 100000 + 10;
const int INTERSECTIONS = 10 + 5;
const llong INF = 1e18;
const int INTINF = 1e9;
const int MAXLOG = 17;
namespace
{
int cnt;
int n, m;
int s, t;
int h[MAXN];
int x[MAXN];
int left[MAXN];
int right[MAXN];
int y[MAXN];
std::map <int,int> map[MAXN];
bool vis[MAXN * INTERSECTIONS];
llong dist[MAXN * INTERSECTIONS];
std::vector <std::pair <int,int>> g[MAXN * INTERSECTIONS];
int cntNodes;
}
struct Sparse
{
int sparse[MAXLOG][MAXN];
int getLOG[MAXN];
void build(int a[])
{
for (int i = 1 ; i <= n ; ++i)
{
sparse[0][i] = a[i];
}
for (int lg = 1 ; (1 << lg) <= n ; ++lg)
{
for (int i = 1 ; i + (1 << lg) - 1 <= n ; ++i)
{
sparse[lg][i] = std::max(sparse[lg - 1][i], sparse[lg - 1][i + (1 << lg - 1)]);
}
}
for (int i = 1 ; i <= n ; ++i)
{
getLOG[i] = getLOG[i - 1];
if ((1 << getLOG[i] + 1) < i) getLOG[i]++;
}
}
int findMAX(int l, int r)
{
int lg = getLOG[r - l + 1];
return std::max(sparse[lg][l], sparse[lg][r - (1 << lg) + 1]);
}
};
Sparse sparse;
llong solve()
{
for (int i = 1 ; i <= n ; ++i)
{
map[i][0] = ++cnt;
}
sparse.build(h);
for (int i = 1 ; i <= m ; ++i)
{
int prev = left[i];
if (map[left[i]][y[i]] == 0)
{
map[left[i]][y[i]] = ++cnt;
}
while (prev < right[i])
{
int l = prev, r = right[i] + 1, mid;
while (l < r - 1)
{
mid = l + r >> 1;
if (sparse.findMAX(prev + 1, mid) < y[i]) l = mid;
else r = mid;
}
if (map[r][y[i]] == 0)
{
map[r][y[i]] = ++cnt;
}
// std::cout << "here: " << prev << ' ' << r << ' ' << y[i] << '\n';
g[map[prev][y[i]]].push_back({map[r][y[i]], x[r] - x[prev]});
g[map[r][y[i]]].push_back({map[prev][y[i]], x[r] - x[prev]});
prev = r;
}
}
for (int i = 1 ; i <= n ; ++i)
{
auto prev = map[i].begin();
for (auto curr = std::next(map[i].begin()) ; curr != map[i].end() ; ++curr)
{
// std::cout << "edge ver: " << x[i] << ' ' << prev->first << ' ' << x[i] << ' ' << curr->first << '\n';
g[prev->second].push_back({curr->second, curr->first - prev->first});
g[curr->second].push_back({prev->second, curr->first - prev->first});
prev = curr;
}
}
std::priority_queue <std::pair <llong,int>> pq;
std::fill(dist + 1, dist + 1 + cnt, INF);
pq.push({0, map[s][0]});
dist[map[s][0]] = 0;
while (pq.size())
{
auto [d, node] = pq.top();
pq.pop();
if (vis[node])
{
continue;
}
vis[node] = true;
for (const auto &[u, ed] : g[node])
{
if (dist[u] > dist[node] + ed)
{
dist[u] = dist[node] + ed;
pq.push({-dist[u], u});
}
}
}
return (dist[map[t][0]] == INF ? -1 : dist[map[t][0]]);
}
struct Fenwick
{
int tree[MAXN];
void update(int idx, int val)
{
assert(idx != 0);
for (; idx <= n ; idx += idx & (-idx))
{
tree[idx] += val;
}
}
int query(int idx)
{
int res = 0;
for (; idx ; idx -= idx & (-idx))
{
res += tree[idx];
}
return res;
}
int kth(int k)
{
int idx = 0;
for (int lg = MAXLOG - 1 ; lg >= 0 ; --lg)
{
if (idx + (1 << lg) <= n && tree[idx + (1 << lg)] < k)
{
idx += (1 << lg);
k -= tree[idx];
}
}
return idx + 1;
}
};
int lastX[MAXN];
int lastNode[MAXN];
int permY[MAXN];
int order[MAXN];
Fenwick fenwick;
std::vector <int> activate[MAXN];
std::vector <int> deactivate[MAXN];
int firstBigger[MAXN];
llong solveSpecial()
{
map[1][0] = ++cnt;
map[n][0] = ++cnt;
std::iota(permY + 1, permY + 1 + m, 1);
std::sort(permY + 1, permY + 1 + m, [&](int a, int b)
{
return y[a] < y[b];
});
for (int i = 1 ; i <= m ; ++i)
{
order[permY[i]] = i;
}
firstBigger[permY[m]] = m + 1;
for (int i = m - 1 ; i >= 1 ; --i)
{
firstBigger[permY[i]] = firstBigger[permY[i + 1]];
while (y[permY[firstBigger[permY[i]] - 1]] > y[permY[i]])
{
firstBigger[permY[i]]--;
}
}
for (int i = 1 ; i <= m ; ++i)
{
activate[left[i]].push_back(i);
deactivate[right[i] + 1].push_back(i);
}
for (int i = 1 ; i <= m ; ++i)
{
for (const int &idx : activate[i])
{
fenwick.update(order[idx], 1);
}
for (const int &idx : deactivate[i])
{
fenwick.update(order[idx], -1);
}
for (const int &idx : activate[i])
{
map[i][y[idx]] = ++cnt;
lastNode[idx] = cnt;
lastX[idx] = x[i];
}
for (const int &idx : activate[i])
{
int below = fenwick.query(order[idx] - 1);
if (fenwick.query(firstBigger[idx] - 1) > fenwick.query(order[idx]))
{
below = fenwick.query(firstBigger[idx] - 1);
}
if (below)
{
int newIdx = permY[fenwick.kth(below)];
if (lastX[newIdx] != x[i])
{
map[i][y[newIdx]] = ++cnt;
g[lastNode[newIdx]].push_back({map[i][y[newIdx]], x[i] - lastX[newIdx]});
g[map[i][y[newIdx]]].push_back({lastNode[newIdx], x[i] - lastX[newIdx]});
lastX[newIdx] = x[i];
lastNode[newIdx] = map[i][y[newIdx]];
}
g[map[i][y[newIdx]]].push_back({map[i][y[idx]], y[idx] - y[newIdx]});
g[map[i][y[idx]]].push_back({map[i][y[newIdx]], y[idx] - y[newIdx]});
}
}
for (const int &idx : deactivate[i + 1])
{
if (lastX[idx] != x[i])
{
map[i][y[idx]] = ++cnt;
g[lastNode[idx]].push_back({cnt, x[i] - lastX[idx]});
g[cnt].push_back({lastNode[idx], x[i] - lastX[idx]});
lastX[idx] = x[i];
lastNode[idx] = cnt;
}
int below = fenwick.query(order[idx] - 1);
if (fenwick.query(firstBigger[idx] - 1) > fenwick.query(order[idx]))
{
below = fenwick.query(firstBigger[idx] - 1);
}
if (below)
{
int newIdx = permY[fenwick.kth(below)];
if (lastX[newIdx] != x[i])
{
map[i][y[newIdx]] = ++cnt;
g[lastNode[newIdx]].push_back({cnt, x[i] - lastX[newIdx]});
g[cnt].push_back({lastNode[newIdx], x[i] - lastX[newIdx]});
lastX[newIdx] = x[i];
lastNode[newIdx] = cnt;
}
g[map[i][y[newIdx]]].push_back({map[i][y[idx]], y[idx] - y[newIdx]});
g[map[i][y[idx]]].push_back({map[i][y[newIdx]], y[idx] - y[newIdx]});
}
}
}
if (map[1].size() > 1)
{
auto node = std::next(map[1].begin());
g[map[1][0]].push_back({node->second, node->first});
g[node->second].push_back({map[1][0], node->first});
}
if (map[n].size() > 1)
{
auto node = std::next(map[n].begin());
g[map[n][0]].push_back({node->second, node->first});
g[node->second].push_back({map[n][0], node->first});
}
std::priority_queue <std::pair <llong,int>> pq;
std::fill(dist + 1, dist + 1 + cnt, INF);
pq.push({0, map[s][0]});
dist[map[s][0]] = 0;
while (pq.size())
{
auto [d, node] = pq.top();
pq.pop();
if (vis[node])
{
continue;
}
vis[node] = true;
for (const auto &[u, ed] : g[node])
{
if (dist[u] > dist[node] + ed)
{
dist[u] = dist[node] + ed;
pq.push({-dist[u], u});
}
}
}
return (dist[map[t][0]] == INF ? -1 : dist[map[t][0]]);
}
long long min_distance(std::vector<int> x, std::vector<int> h, std::vector<int> l, std::vector<int> r, std::vector<int> y, int s, int t)
{
n = x.size();
m = l.size();
::s = s + 1; ::t = t + 1;
for (int i = 0 ; i < n ; ++i)
{
::h[i + 1] = h[i];
::x[i + 1] = x[i];
}
std::vector <int> perm(m);
std::iota(perm.begin(), perm.end(), 0);
std::sort(perm.begin(), perm.end(), [&](int x, int y)
{
return l[x] < l[y];
});
for (int i = 0 ; i < m ; ++i)
{
::left[i + 1] = l[perm[i]] + 1;
::right[i + 1] = r[perm[i]] + 1;
::y[i + 1] = y[perm[i]];
}
if (::s == 1 && ::t == n) return solveSpecial();
return solve();
}
Compilation message
walk.cpp: In member function 'void Sparse::build(int*)':
walk.cpp:51:89: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
51 | sparse[lg][i] = std::max(sparse[lg - 1][i], sparse[lg - 1][i + (1 << lg - 1)]);
| ~~~^~~
walk.cpp:58:33: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
58 | if ((1 << getLOG[i] + 1) < i) getLOG[i]++;
| ~~~~~~~~~~^~~
walk.cpp: In function 'llong solve()':
walk.cpp:91:25: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
91 | mid = l + r >> 1;
| ~~^~~
walk.cpp: At global scope:
walk.cpp:32:9: warning: '{anonymous}::cntNodes' defined but not used [-Wunused-variable]
32 | int cntNodes;
| ^~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
8 ms |
49496 KB |
Output is correct |
| 2 |
Incorrect |
9 ms |
49448 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
10 ms |
49500 KB |
Output is correct |
| 2 |
Incorrect |
8 ms |
49612 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
49 ms |
58964 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
49 ms |
58964 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
8 ms |
49496 KB |
Output is correct |
| 2 |
Incorrect |
9 ms |
49448 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
