/*
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx2,fma,bmi,bmi2,sse4.2,popcnt,lzcnt")
*/
#include <bits/stdc++.h>
#define taskname ""
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define int long long
#define i64 long long
#define pb push_back
#define ff first
#define ss second
#define isz(x) (int)x.size()
using namespace std;
const int mxN = 3e5 + 5;
const int mxM = 3e5 + 5;
const int mod = 1e9 + 7;
const i64 oo = 1e18;
int n, m;
bool vis[mxN];
vector<pair<int, int>> G[mxN], Gn[mxN];
int w[mxM], max_w[mxM];
i64 dis1[mxN], disn[mxN];
pair<int, int> edges[mxM];
i64 dijkstra() {
fill(dis1 + 1, dis1 + n + 1, oo);
priority_queue<pair<i64, int>, vector<pair<i64, int>>, greater<pair<i64, int>>> pq;
dis1[1] = 0; pq.emplace(0, 1);
while (not pq.empty()) {
i64 cdis = pq.top().ff;
int v = pq.top().ss;
pq.pop();
if (cdis != dis1[v]) continue;
for (auto [u, ei] : G[v]) {
if (dis1[v] + w[ei] < dis1[u]) {
dis1[u] = dis1[v] + w[ei];
pq.emplace(dis1[u], u);
}
}
}
fill(disn + 1, disn + n + 1, oo);
disn[n] = 0; pq.emplace(0, n);
while (not pq.empty()) {
i64 cdis = pq.top().ff;
int v = pq.top().ss;
pq.pop();
if (cdis != disn[v]) continue;
for (auto [u, ei] : G[v]) {
if (disn[v] + w[ei] < disn[u]) {
disn[u] = disn[v] + w[ei];
pq.emplace(disn[u], u);
}
}
}
return dis1[n];
}
i64 res_check;
bool vis_n[mxN];
int low[mxN], tin[mxN], tdfs;
void reset_check() {
res_check = -1, tdfs = 0;
for (int i = 1; i <= n; ++i) {
G[i].clear();
vis[i] = vis_n[i] = false;
}
}
void dfs(int v, int p) {
vis[v] = true, vis_n[v] = (v == n);
tin[v] = low[v] = ++tdfs;
for (auto [u, ei] : G[v]) {
if (u == p) continue;
if (vis[u]) {
low[v] = min(low[v], tin[u]);
}
else {
dfs(u, v);
low[v] = min(low[v], low[u]);
if (low[u] > tin[v] && vis_n[u]) {
res_check = max(res_check, min(dis1[u] + disn[v], dis1[v] + disn[u]) + w[ei] + max_w[ei]);
}
vis_n[v] |= vis_n[u];
}
}
}
bool check(i64 val) {
reset_check();
for (int i = 1; i <= m; ++i) {
int u = edges[i].ff, v = edges[i].ss;
if (min(dis1[u] + disn[v], dis1[v] + disn[u]) + w[i] <= val) {
// cout << u << " " << v << endl;
G[u].emplace_back(v, i);
G[v].emplace_back(u, i);
}
}
dfs(1, 0);
// cout << res_check << endl << endl;
return !(res_check > val);
}
void solve() {
cin >> n >> m;
for (int i = 1; i <= m; ++i) {
int u, v, cw;
cin >> u >> v >> cw;
G[u].emplace_back(v, i);
G[v].emplace_back(u, i);
edges[i] = {u, v};
w[i] = max_w[i - 1] = cw;
}
for (int i = m - 1; i >= 1; --i)
max_w[i] = max(max_w[i], max_w[i + 1]);
i64 miin = dijkstra();
i64 l = miin, r = miin + 1e9;
while (l < r) {
i64 mid = (l + r) >> 1;
if (check(mid)) r = mid;
else l = mid + 1;
}
cout << l << endl;
}
signed main() {
#ifndef CDuongg
if(fopen(taskname".inp", "r"))
assert(freopen(taskname".inp", "r", stdin)), assert(freopen(taskname".out", "w", stdout));
#else
freopen("bai3.inp", "r", stdin);
freopen("bai3.out", "w", stdout);
auto start = chrono::high_resolution_clock::now();
#endif
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int t = 1; //cin >> t;
while(t--) solve();
#ifdef CDuongg
auto end = chrono::high_resolution_clock::now();
cout << "\n"; for(int i = 1; i <= 100; ++i) cout << '=';
cout << "\nExecution time: " << chrono::duration_cast<chrono::milliseconds> (end - start).count() << "[ms]" << endl;
cout << "Check array size pls sir" << endl;
#endif
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
27224 KB |
Output is correct |
2 |
Correct |
5 ms |
27224 KB |
Output is correct |
3 |
Correct |
5 ms |
27228 KB |
Output is correct |
4 |
Correct |
5 ms |
27056 KB |
Output is correct |
5 |
Correct |
5 ms |
27228 KB |
Output is correct |
6 |
Correct |
5 ms |
27280 KB |
Output is correct |
7 |
Correct |
5 ms |
27228 KB |
Output is correct |
8 |
Correct |
5 ms |
27484 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
27224 KB |
Output is correct |
2 |
Correct |
5 ms |
27224 KB |
Output is correct |
3 |
Correct |
5 ms |
27228 KB |
Output is correct |
4 |
Correct |
5 ms |
27056 KB |
Output is correct |
5 |
Correct |
5 ms |
27228 KB |
Output is correct |
6 |
Correct |
5 ms |
27280 KB |
Output is correct |
7 |
Correct |
5 ms |
27228 KB |
Output is correct |
8 |
Correct |
5 ms |
27484 KB |
Output is correct |
9 |
Correct |
6 ms |
27228 KB |
Output is correct |
10 |
Correct |
6 ms |
27284 KB |
Output is correct |
11 |
Correct |
6 ms |
27288 KB |
Output is correct |
12 |
Correct |
6 ms |
27228 KB |
Output is correct |
13 |
Correct |
6 ms |
27484 KB |
Output is correct |
14 |
Correct |
6 ms |
27480 KB |
Output is correct |
15 |
Correct |
6 ms |
27484 KB |
Output is correct |
16 |
Correct |
6 ms |
27480 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
409 ms |
50008 KB |
Output is correct |
2 |
Correct |
370 ms |
56808 KB |
Output is correct |
3 |
Correct |
381 ms |
56676 KB |
Output is correct |
4 |
Correct |
397 ms |
56628 KB |
Output is correct |
5 |
Correct |
389 ms |
56652 KB |
Output is correct |
6 |
Correct |
373 ms |
57224 KB |
Output is correct |
7 |
Correct |
369 ms |
56912 KB |
Output is correct |
8 |
Correct |
384 ms |
57228 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
392 ms |
50552 KB |
Output is correct |
2 |
Correct |
409 ms |
57188 KB |
Output is correct |
3 |
Correct |
366 ms |
56588 KB |
Output is correct |
4 |
Correct |
377 ms |
57276 KB |
Output is correct |
5 |
Correct |
372 ms |
56752 KB |
Output is correct |
6 |
Correct |
387 ms |
56748 KB |
Output is correct |
7 |
Correct |
371 ms |
56724 KB |
Output is correct |
8 |
Correct |
385 ms |
57060 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1617 ms |
58268 KB |
Output is correct |
2 |
Correct |
631 ms |
47964 KB |
Output is correct |
3 |
Correct |
966 ms |
55600 KB |
Output is correct |
4 |
Correct |
918 ms |
55536 KB |
Output is correct |
5 |
Correct |
908 ms |
55548 KB |
Output is correct |
6 |
Correct |
940 ms |
55888 KB |
Output is correct |
7 |
Correct |
983 ms |
55732 KB |
Output is correct |
8 |
Correct |
897 ms |
55792 KB |
Output is correct |
9 |
Correct |
929 ms |
55608 KB |
Output is correct |
10 |
Correct |
918 ms |
56148 KB |
Output is correct |
11 |
Correct |
928 ms |
55632 KB |
Output is correct |
12 |
Correct |
1642 ms |
58700 KB |
Output is correct |
13 |
Correct |
944 ms |
55888 KB |
Output is correct |
14 |
Correct |
341 ms |
65112 KB |
Output is correct |
15 |
Correct |
358 ms |
65112 KB |
Output is correct |
16 |
Correct |
1547 ms |
58924 KB |
Output is correct |
17 |
Correct |
1521 ms |
58228 KB |
Output is correct |
18 |
Correct |
1536 ms |
58600 KB |
Output is correct |
19 |
Correct |
622 ms |
47956 KB |
Output is correct |
20 |
Correct |
628 ms |
47952 KB |
Output is correct |
21 |
Correct |
626 ms |
47956 KB |
Output is correct |
22 |
Correct |
624 ms |
48212 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1617 ms |
58268 KB |
Output is correct |
2 |
Correct |
631 ms |
47964 KB |
Output is correct |
3 |
Correct |
966 ms |
55600 KB |
Output is correct |
4 |
Correct |
918 ms |
55536 KB |
Output is correct |
5 |
Correct |
908 ms |
55548 KB |
Output is correct |
6 |
Correct |
940 ms |
55888 KB |
Output is correct |
7 |
Correct |
983 ms |
55732 KB |
Output is correct |
8 |
Correct |
897 ms |
55792 KB |
Output is correct |
9 |
Correct |
929 ms |
55608 KB |
Output is correct |
10 |
Correct |
918 ms |
56148 KB |
Output is correct |
11 |
Correct |
928 ms |
55632 KB |
Output is correct |
12 |
Correct |
1642 ms |
58700 KB |
Output is correct |
13 |
Correct |
944 ms |
55888 KB |
Output is correct |
14 |
Correct |
341 ms |
65112 KB |
Output is correct |
15 |
Correct |
358 ms |
65112 KB |
Output is correct |
16 |
Correct |
1547 ms |
58924 KB |
Output is correct |
17 |
Correct |
1521 ms |
58228 KB |
Output is correct |
18 |
Correct |
1536 ms |
58600 KB |
Output is correct |
19 |
Correct |
622 ms |
47956 KB |
Output is correct |
20 |
Correct |
628 ms |
47952 KB |
Output is correct |
21 |
Correct |
626 ms |
47956 KB |
Output is correct |
22 |
Correct |
624 ms |
48212 KB |
Output is correct |
23 |
Correct |
1532 ms |
58856 KB |
Output is correct |
24 |
Correct |
638 ms |
52484 KB |
Output is correct |
25 |
Correct |
904 ms |
59520 KB |
Output is correct |
26 |
Correct |
840 ms |
59588 KB |
Output is correct |
27 |
Correct |
856 ms |
59620 KB |
Output is correct |
28 |
Correct |
843 ms |
59856 KB |
Output is correct |
29 |
Correct |
840 ms |
59780 KB |
Output is correct |
30 |
Correct |
855 ms |
60140 KB |
Output is correct |
31 |
Correct |
856 ms |
59736 KB |
Output is correct |
32 |
Correct |
861 ms |
59804 KB |
Output is correct |
33 |
Correct |
862 ms |
60080 KB |
Output is correct |
34 |
Correct |
1487 ms |
63060 KB |
Output is correct |
35 |
Correct |
886 ms |
59956 KB |
Output is correct |
36 |
Correct |
308 ms |
63356 KB |
Output is correct |
37 |
Correct |
332 ms |
64556 KB |
Output is correct |
38 |
Correct |
1533 ms |
62928 KB |
Output is correct |
39 |
Correct |
1468 ms |
62612 KB |
Output is correct |
40 |
Correct |
1520 ms |
63448 KB |
Output is correct |
41 |
Correct |
648 ms |
52308 KB |
Output is correct |
42 |
Correct |
634 ms |
52480 KB |
Output is correct |
43 |
Correct |
667 ms |
52456 KB |
Output is correct |
44 |
Correct |
662 ms |
52560 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
27224 KB |
Output is correct |
2 |
Correct |
5 ms |
27224 KB |
Output is correct |
3 |
Correct |
5 ms |
27228 KB |
Output is correct |
4 |
Correct |
5 ms |
27056 KB |
Output is correct |
5 |
Correct |
5 ms |
27228 KB |
Output is correct |
6 |
Correct |
5 ms |
27280 KB |
Output is correct |
7 |
Correct |
5 ms |
27228 KB |
Output is correct |
8 |
Correct |
5 ms |
27484 KB |
Output is correct |
9 |
Correct |
6 ms |
27228 KB |
Output is correct |
10 |
Correct |
6 ms |
27284 KB |
Output is correct |
11 |
Correct |
6 ms |
27288 KB |
Output is correct |
12 |
Correct |
6 ms |
27228 KB |
Output is correct |
13 |
Correct |
6 ms |
27484 KB |
Output is correct |
14 |
Correct |
6 ms |
27480 KB |
Output is correct |
15 |
Correct |
6 ms |
27484 KB |
Output is correct |
16 |
Correct |
6 ms |
27480 KB |
Output is correct |
17 |
Correct |
409 ms |
50008 KB |
Output is correct |
18 |
Correct |
370 ms |
56808 KB |
Output is correct |
19 |
Correct |
381 ms |
56676 KB |
Output is correct |
20 |
Correct |
397 ms |
56628 KB |
Output is correct |
21 |
Correct |
389 ms |
56652 KB |
Output is correct |
22 |
Correct |
373 ms |
57224 KB |
Output is correct |
23 |
Correct |
369 ms |
56912 KB |
Output is correct |
24 |
Correct |
384 ms |
57228 KB |
Output is correct |
25 |
Correct |
392 ms |
50552 KB |
Output is correct |
26 |
Correct |
409 ms |
57188 KB |
Output is correct |
27 |
Correct |
366 ms |
56588 KB |
Output is correct |
28 |
Correct |
377 ms |
57276 KB |
Output is correct |
29 |
Correct |
372 ms |
56752 KB |
Output is correct |
30 |
Correct |
387 ms |
56748 KB |
Output is correct |
31 |
Correct |
371 ms |
56724 KB |
Output is correct |
32 |
Correct |
385 ms |
57060 KB |
Output is correct |
33 |
Correct |
1617 ms |
58268 KB |
Output is correct |
34 |
Correct |
631 ms |
47964 KB |
Output is correct |
35 |
Correct |
966 ms |
55600 KB |
Output is correct |
36 |
Correct |
918 ms |
55536 KB |
Output is correct |
37 |
Correct |
908 ms |
55548 KB |
Output is correct |
38 |
Correct |
940 ms |
55888 KB |
Output is correct |
39 |
Correct |
983 ms |
55732 KB |
Output is correct |
40 |
Correct |
897 ms |
55792 KB |
Output is correct |
41 |
Correct |
929 ms |
55608 KB |
Output is correct |
42 |
Correct |
918 ms |
56148 KB |
Output is correct |
43 |
Correct |
928 ms |
55632 KB |
Output is correct |
44 |
Correct |
1642 ms |
58700 KB |
Output is correct |
45 |
Correct |
944 ms |
55888 KB |
Output is correct |
46 |
Correct |
341 ms |
65112 KB |
Output is correct |
47 |
Correct |
358 ms |
65112 KB |
Output is correct |
48 |
Correct |
1547 ms |
58924 KB |
Output is correct |
49 |
Correct |
1521 ms |
58228 KB |
Output is correct |
50 |
Correct |
1536 ms |
58600 KB |
Output is correct |
51 |
Correct |
622 ms |
47956 KB |
Output is correct |
52 |
Correct |
628 ms |
47952 KB |
Output is correct |
53 |
Correct |
626 ms |
47956 KB |
Output is correct |
54 |
Correct |
624 ms |
48212 KB |
Output is correct |
55 |
Correct |
1532 ms |
58856 KB |
Output is correct |
56 |
Correct |
638 ms |
52484 KB |
Output is correct |
57 |
Correct |
904 ms |
59520 KB |
Output is correct |
58 |
Correct |
840 ms |
59588 KB |
Output is correct |
59 |
Correct |
856 ms |
59620 KB |
Output is correct |
60 |
Correct |
843 ms |
59856 KB |
Output is correct |
61 |
Correct |
840 ms |
59780 KB |
Output is correct |
62 |
Correct |
855 ms |
60140 KB |
Output is correct |
63 |
Correct |
856 ms |
59736 KB |
Output is correct |
64 |
Correct |
861 ms |
59804 KB |
Output is correct |
65 |
Correct |
862 ms |
60080 KB |
Output is correct |
66 |
Correct |
1487 ms |
63060 KB |
Output is correct |
67 |
Correct |
886 ms |
59956 KB |
Output is correct |
68 |
Correct |
308 ms |
63356 KB |
Output is correct |
69 |
Correct |
332 ms |
64556 KB |
Output is correct |
70 |
Correct |
1533 ms |
62928 KB |
Output is correct |
71 |
Correct |
1468 ms |
62612 KB |
Output is correct |
72 |
Correct |
1520 ms |
63448 KB |
Output is correct |
73 |
Correct |
648 ms |
52308 KB |
Output is correct |
74 |
Correct |
634 ms |
52480 KB |
Output is correct |
75 |
Correct |
667 ms |
52456 KB |
Output is correct |
76 |
Correct |
662 ms |
52560 KB |
Output is correct |
77 |
Correct |
353 ms |
56764 KB |
Output is correct |
78 |
Correct |
372 ms |
54552 KB |
Output is correct |
79 |
Correct |
270 ms |
62052 KB |
Output is correct |
80 |
Correct |
293 ms |
61916 KB |
Output is correct |
81 |
Correct |
281 ms |
61776 KB |
Output is correct |
82 |
Correct |
288 ms |
61848 KB |
Output is correct |
83 |
Correct |
257 ms |
62176 KB |
Output is correct |
84 |
Correct |
276 ms |
62252 KB |
Output is correct |
85 |
Correct |
273 ms |
62072 KB |
Output is correct |
86 |
Correct |
277 ms |
61900 KB |
Output is correct |
87 |
Correct |
276 ms |
62288 KB |
Output is correct |
88 |
Correct |
330 ms |
56300 KB |
Output is correct |
89 |
Correct |
273 ms |
62288 KB |
Output is correct |
90 |
Correct |
341 ms |
63856 KB |
Output is correct |
91 |
Correct |
353 ms |
65384 KB |
Output is correct |
92 |
Correct |
338 ms |
56544 KB |
Output is correct |
93 |
Correct |
312 ms |
56472 KB |
Output is correct |
94 |
Correct |
312 ms |
56168 KB |
Output is correct |
95 |
Correct |
360 ms |
54584 KB |
Output is correct |
96 |
Correct |
368 ms |
54564 KB |
Output is correct |
97 |
Correct |
364 ms |
54612 KB |
Output is correct |
98 |
Correct |
410 ms |
54588 KB |
Output is correct |