//https://oj.uz/problem/view/IZhO18_plan
//binary lifting on mst
#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
using pli = pair<ll,int>;
const int N = 1e5 + 5, M = 5e5 + 5;
const ll inf = 1e18; // beaware maybe not enough
vector<pli> adj[N];
ll D[N], mn[N][20];
bool vis[N];
tuple<int,int,int> E[M];
tuple<ll,int,int> edges[M];
int p[N], up[N][20], dep[N], LOG, sz[N];
int fp(int x){if(x == p[x]) return x; return p[x] = fp(p[x]);}
void dfs(int u, int p, ll wp){
up[u][0] = p; mn[u][0] = min(mn[u][0], wp);
if(u != p) dep[u] = dep[p] + 1;
for(int j = 1; j<LOG; ++j){
up[u][j] = up[up[u][j-1]][j-1];
mn[u][j] = min(mn[u][j-1], mn[up[u][j-1]][j-1]);
}
for(pli it: adj[u]){
ll w = it.first; int v = it.second;
if(v != p) dfs(v, u, w);
}
}
pair<ll,int> get_lca(int u, int v){
ll w = inf;
if(u == v) return make_pair(w, u);
if(dep[u] < dep[v]) swap(u, v);
for(int j = LOG-1; j>=0; --j) if((dep[u]-dep[v])>>j&1) w = min(w, mn[u][j]), u = up[u][j];
if(u == v) return make_pair(w, u);
for(int j = LOG-1; j>=0; --j) if(up[u][j] != up[v][j]){w = min({w, mn[u][j], mn[v][j]}); u = up[u][j]; v = up[v][j];}
return make_pair(min({w, mn[u][0], mn[v][0]}), up[u][0]);
}
signed main(){
int n, m; scanf("%d %d", &n, &m); LOG = 32 - __builtin_clz(n);
for(int i = 0, u, v, w; i<m; ++i){
scanf("%d %d %d", &u, &v, &w); --u; --v;
E[i] = make_tuple(u, v, w);
adj[u].emplace_back(w, v); adj[v].emplace_back(w, u);
}
priority_queue<pli, vector<pli>, greater<pli>> pq;
fill(D, D+n, inf); fill(vis, vis+n, false);
int k; scanf("%d", &k);
for(int i = 0, u; i<k; ++i) scanf("%d", &u), pq.emplace(D[u-1] = 0, u-1);
while(!pq.empty()){
int u = pq.top().second; pq.pop();
if(vis[u]) continue; vis[u] = true;
for(pli it: adj[u]){
ll w = it.first; int v = it.second;
if(D[u] < inf && D[u] + w < D[v]) pq.emplace(D[v] = D[u] + w, v);
}
}
for(int i = 0; i<m; ++i){
int u, v, _; tie(u, v, _) = E[i];
edges[i] = make_tuple(min(D[u], D[v]), u, v);
}
for(int i = 0; i<n; ++i){
adj[i].clear(); p[i] = i; sz[i] = 1; fill(mn[i], mn[i]+LOG, inf);
}
sort(edges, edges+m, greater<tuple<ll,int,int>>());
for(int i = 0; i<m; ++i){
ll w; int u, v; tie(w, u, v) = edges[i];
if(fp(u) != fp(v)){
int pu = fp(u), pv = fp(v);
if(sz[pu] < sz[pv]) swap(pu, pv);
sz[pu] += sz[pv]; p[pv] = pu;
adj[u].emplace_back(w, v); adj[v].emplace_back(w, u);
}
}
dfs(0, 0, inf);
int q; scanf("%d", &q);
while(q--){
int u, v; scanf("%d %d", &u, &v); --u; --v;
pair<ll,int> tmp = get_lca(u, v);
ll w = tmp.first; int lca = tmp.second;
printf("%lld\n", w);
}
}
Compilation message
plan.cpp: In function 'int main()':
plan.cpp:50:3: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
50 | if(vis[u]) continue; vis[u] = true;
| ^~
plan.cpp:50:24: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
50 | if(vis[u]) continue; vis[u] = true;
| ^~~
plan.cpp:78:25: warning: unused variable 'lca' [-Wunused-variable]
78 | ll w = tmp.first; int lca = tmp.second;
| ^~~
plan.cpp:38:17: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
38 | int n, m; scanf("%d %d", &n, &m); LOG = 32 - __builtin_clz(n);
| ~~~~~^~~~~~~~~~~~~~~~~
plan.cpp:40:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
40 | scanf("%d %d %d", &u, &v, &w); --u; --v;
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
plan.cpp:46:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
46 | int k; scanf("%d", &k);
| ~~~~~^~~~~~~~~~
plan.cpp:47:35: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
47 | for(int i = 0, u; i<k; ++i) scanf("%d", &u), pq.emplace(D[u-1] = 0, u-1);
| ~~~~~^~~~~~~~~~
plan.cpp:74:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
74 | int q; scanf("%d", &q);
| ~~~~~^~~~~~~~~~
plan.cpp:76:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
76 | int u, v; scanf("%d %d", &u, &v); --u; --v;
| ~~~~~^~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
14944 KB |
Output is correct |
2 |
Correct |
3 ms |
15192 KB |
Output is correct |
3 |
Correct |
5 ms |
15164 KB |
Output is correct |
4 |
Correct |
2 ms |
14936 KB |
Output is correct |
5 |
Correct |
3 ms |
15196 KB |
Output is correct |
6 |
Correct |
3 ms |
15196 KB |
Output is correct |
7 |
Correct |
3 ms |
14936 KB |
Output is correct |
8 |
Correct |
2 ms |
15196 KB |
Output is correct |
9 |
Correct |
4 ms |
15196 KB |
Output is correct |
10 |
Correct |
3 ms |
15192 KB |
Output is correct |
11 |
Correct |
3 ms |
15172 KB |
Output is correct |
12 |
Correct |
3 ms |
15196 KB |
Output is correct |
13 |
Correct |
3 ms |
15196 KB |
Output is correct |
14 |
Correct |
3 ms |
15196 KB |
Output is correct |
15 |
Correct |
3 ms |
15196 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
14944 KB |
Output is correct |
2 |
Correct |
3 ms |
15192 KB |
Output is correct |
3 |
Correct |
5 ms |
15164 KB |
Output is correct |
4 |
Correct |
2 ms |
14936 KB |
Output is correct |
5 |
Correct |
3 ms |
15196 KB |
Output is correct |
6 |
Correct |
3 ms |
15196 KB |
Output is correct |
7 |
Correct |
3 ms |
14936 KB |
Output is correct |
8 |
Correct |
2 ms |
15196 KB |
Output is correct |
9 |
Correct |
4 ms |
15196 KB |
Output is correct |
10 |
Correct |
3 ms |
15192 KB |
Output is correct |
11 |
Correct |
3 ms |
15172 KB |
Output is correct |
12 |
Correct |
3 ms |
15196 KB |
Output is correct |
13 |
Correct |
3 ms |
15196 KB |
Output is correct |
14 |
Correct |
3 ms |
15196 KB |
Output is correct |
15 |
Correct |
3 ms |
15196 KB |
Output is correct |
16 |
Correct |
138 ms |
41636 KB |
Output is correct |
17 |
Correct |
430 ms |
75616 KB |
Output is correct |
18 |
Correct |
27 ms |
18144 KB |
Output is correct |
19 |
Correct |
113 ms |
44352 KB |
Output is correct |
20 |
Correct |
477 ms |
75740 KB |
Output is correct |
21 |
Correct |
226 ms |
52928 KB |
Output is correct |
22 |
Correct |
144 ms |
48044 KB |
Output is correct |
23 |
Correct |
411 ms |
75464 KB |
Output is correct |
24 |
Correct |
462 ms |
75496 KB |
Output is correct |
25 |
Correct |
429 ms |
75460 KB |
Output is correct |
26 |
Correct |
111 ms |
44092 KB |
Output is correct |
27 |
Correct |
130 ms |
44096 KB |
Output is correct |
28 |
Correct |
112 ms |
44096 KB |
Output is correct |
29 |
Correct |
117 ms |
44180 KB |
Output is correct |
30 |
Correct |
132 ms |
44328 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
14940 KB |
Output is correct |
2 |
Correct |
3 ms |
14940 KB |
Output is correct |
3 |
Correct |
2 ms |
14940 KB |
Output is correct |
4 |
Correct |
2 ms |
15196 KB |
Output is correct |
5 |
Correct |
2 ms |
15152 KB |
Output is correct |
6 |
Correct |
3 ms |
15092 KB |
Output is correct |
7 |
Correct |
2 ms |
15176 KB |
Output is correct |
8 |
Correct |
3 ms |
14940 KB |
Output is correct |
9 |
Correct |
3 ms |
14940 KB |
Output is correct |
10 |
Correct |
2 ms |
14940 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
188 ms |
51504 KB |
Output is correct |
2 |
Correct |
382 ms |
74516 KB |
Output is correct |
3 |
Correct |
377 ms |
74512 KB |
Output is correct |
4 |
Correct |
103 ms |
44368 KB |
Output is correct |
5 |
Correct |
370 ms |
74496 KB |
Output is correct |
6 |
Correct |
369 ms |
74340 KB |
Output is correct |
7 |
Correct |
367 ms |
74488 KB |
Output is correct |
8 |
Correct |
386 ms |
74640 KB |
Output is correct |
9 |
Correct |
364 ms |
74508 KB |
Output is correct |
10 |
Correct |
391 ms |
74496 KB |
Output is correct |
11 |
Correct |
365 ms |
74520 KB |
Output is correct |
12 |
Correct |
397 ms |
74524 KB |
Output is correct |
13 |
Correct |
393 ms |
74432 KB |
Output is correct |
14 |
Correct |
376 ms |
74484 KB |
Output is correct |
15 |
Correct |
360 ms |
74864 KB |
Output is correct |
16 |
Correct |
364 ms |
74544 KB |
Output is correct |
17 |
Correct |
374 ms |
74528 KB |
Output is correct |
18 |
Correct |
359 ms |
74432 KB |
Output is correct |
19 |
Correct |
88 ms |
45908 KB |
Output is correct |
20 |
Correct |
387 ms |
74616 KB |
Output is correct |
21 |
Correct |
374 ms |
73996 KB |
Output is correct |
22 |
Correct |
83 ms |
43272 KB |
Output is correct |
23 |
Correct |
92 ms |
42440 KB |
Output is correct |
24 |
Correct |
73 ms |
43048 KB |
Output is correct |
25 |
Correct |
72 ms |
43072 KB |
Output is correct |
26 |
Correct |
94 ms |
42980 KB |
Output is correct |
27 |
Correct |
88 ms |
45652 KB |
Output is correct |
28 |
Correct |
79 ms |
43332 KB |
Output is correct |
29 |
Correct |
87 ms |
45060 KB |
Output is correct |
30 |
Correct |
73 ms |
43068 KB |
Output is correct |
31 |
Correct |
92 ms |
45136 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
14944 KB |
Output is correct |
2 |
Correct |
3 ms |
15192 KB |
Output is correct |
3 |
Correct |
5 ms |
15164 KB |
Output is correct |
4 |
Correct |
2 ms |
14936 KB |
Output is correct |
5 |
Correct |
3 ms |
15196 KB |
Output is correct |
6 |
Correct |
3 ms |
15196 KB |
Output is correct |
7 |
Correct |
3 ms |
14936 KB |
Output is correct |
8 |
Correct |
2 ms |
15196 KB |
Output is correct |
9 |
Correct |
4 ms |
15196 KB |
Output is correct |
10 |
Correct |
3 ms |
15192 KB |
Output is correct |
11 |
Correct |
3 ms |
15172 KB |
Output is correct |
12 |
Correct |
3 ms |
15196 KB |
Output is correct |
13 |
Correct |
3 ms |
15196 KB |
Output is correct |
14 |
Correct |
3 ms |
15196 KB |
Output is correct |
15 |
Correct |
3 ms |
15196 KB |
Output is correct |
16 |
Correct |
138 ms |
41636 KB |
Output is correct |
17 |
Correct |
430 ms |
75616 KB |
Output is correct |
18 |
Correct |
27 ms |
18144 KB |
Output is correct |
19 |
Correct |
113 ms |
44352 KB |
Output is correct |
20 |
Correct |
477 ms |
75740 KB |
Output is correct |
21 |
Correct |
226 ms |
52928 KB |
Output is correct |
22 |
Correct |
144 ms |
48044 KB |
Output is correct |
23 |
Correct |
411 ms |
75464 KB |
Output is correct |
24 |
Correct |
462 ms |
75496 KB |
Output is correct |
25 |
Correct |
429 ms |
75460 KB |
Output is correct |
26 |
Correct |
111 ms |
44092 KB |
Output is correct |
27 |
Correct |
130 ms |
44096 KB |
Output is correct |
28 |
Correct |
112 ms |
44096 KB |
Output is correct |
29 |
Correct |
117 ms |
44180 KB |
Output is correct |
30 |
Correct |
132 ms |
44328 KB |
Output is correct |
31 |
Correct |
3 ms |
14940 KB |
Output is correct |
32 |
Correct |
3 ms |
14940 KB |
Output is correct |
33 |
Correct |
2 ms |
14940 KB |
Output is correct |
34 |
Correct |
2 ms |
15196 KB |
Output is correct |
35 |
Correct |
2 ms |
15152 KB |
Output is correct |
36 |
Correct |
3 ms |
15092 KB |
Output is correct |
37 |
Correct |
2 ms |
15176 KB |
Output is correct |
38 |
Correct |
3 ms |
14940 KB |
Output is correct |
39 |
Correct |
3 ms |
14940 KB |
Output is correct |
40 |
Correct |
2 ms |
14940 KB |
Output is correct |
41 |
Correct |
188 ms |
51504 KB |
Output is correct |
42 |
Correct |
382 ms |
74516 KB |
Output is correct |
43 |
Correct |
377 ms |
74512 KB |
Output is correct |
44 |
Correct |
103 ms |
44368 KB |
Output is correct |
45 |
Correct |
370 ms |
74496 KB |
Output is correct |
46 |
Correct |
369 ms |
74340 KB |
Output is correct |
47 |
Correct |
367 ms |
74488 KB |
Output is correct |
48 |
Correct |
386 ms |
74640 KB |
Output is correct |
49 |
Correct |
364 ms |
74508 KB |
Output is correct |
50 |
Correct |
391 ms |
74496 KB |
Output is correct |
51 |
Correct |
365 ms |
74520 KB |
Output is correct |
52 |
Correct |
397 ms |
74524 KB |
Output is correct |
53 |
Correct |
393 ms |
74432 KB |
Output is correct |
54 |
Correct |
376 ms |
74484 KB |
Output is correct |
55 |
Correct |
360 ms |
74864 KB |
Output is correct |
56 |
Correct |
364 ms |
74544 KB |
Output is correct |
57 |
Correct |
374 ms |
74528 KB |
Output is correct |
58 |
Correct |
359 ms |
74432 KB |
Output is correct |
59 |
Correct |
88 ms |
45908 KB |
Output is correct |
60 |
Correct |
387 ms |
74616 KB |
Output is correct |
61 |
Correct |
374 ms |
73996 KB |
Output is correct |
62 |
Correct |
83 ms |
43272 KB |
Output is correct |
63 |
Correct |
92 ms |
42440 KB |
Output is correct |
64 |
Correct |
73 ms |
43048 KB |
Output is correct |
65 |
Correct |
72 ms |
43072 KB |
Output is correct |
66 |
Correct |
94 ms |
42980 KB |
Output is correct |
67 |
Correct |
88 ms |
45652 KB |
Output is correct |
68 |
Correct |
79 ms |
43332 KB |
Output is correct |
69 |
Correct |
87 ms |
45060 KB |
Output is correct |
70 |
Correct |
73 ms |
43068 KB |
Output is correct |
71 |
Correct |
92 ms |
45136 KB |
Output is correct |
72 |
Correct |
252 ms |
52680 KB |
Output is correct |
73 |
Correct |
419 ms |
75784 KB |
Output is correct |
74 |
Correct |
474 ms |
75504 KB |
Output is correct |
75 |
Correct |
433 ms |
75536 KB |
Output is correct |
76 |
Correct |
409 ms |
75592 KB |
Output is correct |
77 |
Correct |
402 ms |
75648 KB |
Output is correct |
78 |
Correct |
398 ms |
75712 KB |
Output is correct |
79 |
Correct |
423 ms |
75460 KB |
Output is correct |
80 |
Correct |
422 ms |
75700 KB |
Output is correct |
81 |
Correct |
423 ms |
75928 KB |
Output is correct |
82 |
Correct |
405 ms |
75452 KB |
Output is correct |
83 |
Correct |
458 ms |
75512 KB |
Output is correct |
84 |
Correct |
427 ms |
75716 KB |
Output is correct |
85 |
Correct |
457 ms |
75960 KB |
Output is correct |
86 |
Correct |
437 ms |
75772 KB |
Output is correct |
87 |
Correct |
411 ms |
75500 KB |
Output is correct |
88 |
Correct |
425 ms |
75984 KB |
Output is correct |
89 |
Correct |
163 ms |
46840 KB |
Output is correct |
90 |
Correct |
474 ms |
75612 KB |
Output is correct |
91 |
Correct |
407 ms |
75056 KB |
Output is correct |
92 |
Correct |
125 ms |
44328 KB |
Output is correct |
93 |
Correct |
148 ms |
44084 KB |
Output is correct |
94 |
Correct |
115 ms |
44008 KB |
Output is correct |
95 |
Correct |
118 ms |
44328 KB |
Output is correct |
96 |
Correct |
163 ms |
43708 KB |
Output is correct |
97 |
Correct |
176 ms |
45684 KB |
Output is correct |
98 |
Correct |
133 ms |
44088 KB |
Output is correct |
99 |
Correct |
188 ms |
47076 KB |
Output is correct |
100 |
Correct |
122 ms |
44284 KB |
Output is correct |