#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define ar array
const int inf = 1e9;
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int k, n, m, q;
cin >> k >> n >> m >> q;
vector <vector<ar<int,2>>> adj(n), rev(n);
for ( int i = 0; i < m; i++ ){
int u, v, w; cin >> u >> v >> w;
adj[u].pb({v, w});
rev[v].pb({u, w});
}
vector <vector<int>> qu(n / k + 1);
for ( int i = 0; i < n; i++ ) qu[i / k].pb(i);
auto calc = [&](int sx, int l, int r, auto &adj){
vector <int> dp(r - l + 1, inf);
dp[sx - l] = 0;
priority_queue <ar<int,2>> q;
q.push({0, sx});
while ( !q.empty() ){
auto [val, u] = q.top();
q.pop(); val *= -1;
if ( val != dp[u - l] ) continue;
for ( auto &[v, w]: adj[u] ){
if ( v < l || v > r ) continue;
if ( dp[v - l] > val + w ){
dp[v - l] = val + w;
q.push({-dp[v - l], v});
}
}
}
return dp;
};
vector <vector<vector<int>>> lf(20, vector <vector<int>> (n)), rg(20, vector <vector<int>> (n));
auto dnc = [&](auto dnc, int l, int r, int lvl) -> void{
if ( l > r ) return;
int m = (l + r) / 2;
for ( auto &u: qu[m] ){
lf[lvl][u] = calc(u, l * k, m * k + k - 1, rev);
rg[lvl][u] = calc(u, m * k, r * k + k - 1, adj);
}
dnc(dnc, l, m - 1, lvl + 1);
dnc(dnc, m + 1, r, lvl + 1);
};
dnc(dnc, 0, (n - 1) / k, 0);
auto qry = [&](int u, int v){
if ( u / k == v / k ) return -1;
int l = 0, r = (n - 1) / k, lvl = 0;
while ( true ){
int m = (l + r) / 2;
int opt = inf, found = 0;
for ( auto &t: qu[m] ){
if ( l * k <= t && (r + 1) *k > t ){
opt = min(opt, lf[lvl][t][u - l * k] + rg[lvl][t][v - m * k]);
found = 1;
}
}
if ( found ){
if ( opt == inf ) opt = -1;
return opt;
}
if ( m * k > v ) r = m - 1;
else l = m + 1;
lvl += 1;
}
};
while ( q-- ){
int u, v; cin >> u >> v;
cout << qry(u, v) << '\n';
}
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
94 ms |
61956 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
135 ms |
63308 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
508 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
508 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
94 ms |
61956 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |