/*
#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 |
27228 KB |
Output is correct |
2 |
Correct |
5 ms |
27228 KB |
Output is correct |
3 |
Correct |
5 ms |
27228 KB |
Output is correct |
4 |
Correct |
5 ms |
27228 KB |
Output is correct |
5 |
Correct |
6 ms |
27228 KB |
Output is correct |
6 |
Correct |
5 ms |
27228 KB |
Output is correct |
7 |
Correct |
5 ms |
27228 KB |
Output is correct |
8 |
Correct |
5 ms |
27228 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
27228 KB |
Output is correct |
2 |
Correct |
5 ms |
27228 KB |
Output is correct |
3 |
Correct |
5 ms |
27228 KB |
Output is correct |
4 |
Correct |
5 ms |
27228 KB |
Output is correct |
5 |
Correct |
6 ms |
27228 KB |
Output is correct |
6 |
Correct |
5 ms |
27228 KB |
Output is correct |
7 |
Correct |
5 ms |
27228 KB |
Output is correct |
8 |
Correct |
5 ms |
27228 KB |
Output is correct |
9 |
Correct |
6 ms |
27224 KB |
Output is correct |
10 |
Correct |
6 ms |
27228 KB |
Output is correct |
11 |
Correct |
6 ms |
27228 KB |
Output is correct |
12 |
Correct |
6 ms |
27224 KB |
Output is correct |
13 |
Correct |
6 ms |
27228 KB |
Output is correct |
14 |
Correct |
6 ms |
27228 KB |
Output is correct |
15 |
Correct |
6 ms |
27228 KB |
Output is correct |
16 |
Correct |
6 ms |
27284 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
388 ms |
50392 KB |
Output is correct |
2 |
Correct |
380 ms |
50064 KB |
Output is correct |
3 |
Correct |
378 ms |
50000 KB |
Output is correct |
4 |
Correct |
384 ms |
50052 KB |
Output is correct |
5 |
Correct |
409 ms |
50180 KB |
Output is correct |
6 |
Correct |
382 ms |
50260 KB |
Output is correct |
7 |
Correct |
379 ms |
50256 KB |
Output is correct |
8 |
Correct |
413 ms |
50440 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
401 ms |
50552 KB |
Output is correct |
2 |
Correct |
430 ms |
50512 KB |
Output is correct |
3 |
Correct |
349 ms |
50064 KB |
Output is correct |
4 |
Correct |
370 ms |
50444 KB |
Output is correct |
5 |
Correct |
404 ms |
50156 KB |
Output is correct |
6 |
Correct |
384 ms |
50180 KB |
Output is correct |
7 |
Correct |
357 ms |
50172 KB |
Output is correct |
8 |
Correct |
410 ms |
50284 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1731 ms |
58296 KB |
Output is correct |
2 |
Correct |
636 ms |
47960 KB |
Output is correct |
3 |
Correct |
983 ms |
55600 KB |
Output is correct |
4 |
Correct |
922 ms |
55636 KB |
Output is correct |
5 |
Correct |
912 ms |
55576 KB |
Output is correct |
6 |
Correct |
971 ms |
55548 KB |
Output is correct |
7 |
Correct |
959 ms |
55892 KB |
Output is correct |
8 |
Correct |
1018 ms |
55788 KB |
Output is correct |
9 |
Correct |
935 ms |
55836 KB |
Output is correct |
10 |
Correct |
1028 ms |
56148 KB |
Output is correct |
11 |
Correct |
924 ms |
55764 KB |
Output is correct |
12 |
Correct |
1692 ms |
58888 KB |
Output is correct |
13 |
Correct |
950 ms |
55728 KB |
Output is correct |
14 |
Correct |
368 ms |
64876 KB |
Output is correct |
15 |
Correct |
341 ms |
65108 KB |
Output is correct |
16 |
Correct |
1710 ms |
58940 KB |
Output is correct |
17 |
Correct |
1613 ms |
58428 KB |
Output is correct |
18 |
Correct |
1643 ms |
58816 KB |
Output is correct |
19 |
Correct |
658 ms |
47944 KB |
Output is correct |
20 |
Correct |
631 ms |
47984 KB |
Output is correct |
21 |
Correct |
668 ms |
47964 KB |
Output is correct |
22 |
Correct |
636 ms |
47952 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1731 ms |
58296 KB |
Output is correct |
2 |
Correct |
636 ms |
47960 KB |
Output is correct |
3 |
Correct |
983 ms |
55600 KB |
Output is correct |
4 |
Correct |
922 ms |
55636 KB |
Output is correct |
5 |
Correct |
912 ms |
55576 KB |
Output is correct |
6 |
Correct |
971 ms |
55548 KB |
Output is correct |
7 |
Correct |
959 ms |
55892 KB |
Output is correct |
8 |
Correct |
1018 ms |
55788 KB |
Output is correct |
9 |
Correct |
935 ms |
55836 KB |
Output is correct |
10 |
Correct |
1028 ms |
56148 KB |
Output is correct |
11 |
Correct |
924 ms |
55764 KB |
Output is correct |
12 |
Correct |
1692 ms |
58888 KB |
Output is correct |
13 |
Correct |
950 ms |
55728 KB |
Output is correct |
14 |
Correct |
368 ms |
64876 KB |
Output is correct |
15 |
Correct |
341 ms |
65108 KB |
Output is correct |
16 |
Correct |
1710 ms |
58940 KB |
Output is correct |
17 |
Correct |
1613 ms |
58428 KB |
Output is correct |
18 |
Correct |
1643 ms |
58816 KB |
Output is correct |
19 |
Correct |
658 ms |
47944 KB |
Output is correct |
20 |
Correct |
631 ms |
47984 KB |
Output is correct |
21 |
Correct |
668 ms |
47964 KB |
Output is correct |
22 |
Correct |
636 ms |
47952 KB |
Output is correct |
23 |
Correct |
1621 ms |
58864 KB |
Output is correct |
24 |
Correct |
673 ms |
48008 KB |
Output is correct |
25 |
Correct |
843 ms |
55496 KB |
Output is correct |
26 |
Correct |
885 ms |
55532 KB |
Output is correct |
27 |
Correct |
836 ms |
55552 KB |
Output is correct |
28 |
Correct |
817 ms |
55888 KB |
Output is correct |
29 |
Correct |
880 ms |
55692 KB |
Output is correct |
30 |
Correct |
851 ms |
55908 KB |
Output is correct |
31 |
Correct |
870 ms |
55864 KB |
Output is correct |
32 |
Correct |
884 ms |
55512 KB |
Output is correct |
33 |
Correct |
893 ms |
55640 KB |
Output is correct |
34 |
Correct |
1546 ms |
58720 KB |
Output is correct |
35 |
Correct |
898 ms |
55832 KB |
Output is correct |
36 |
Correct |
329 ms |
59532 KB |
Output is correct |
37 |
Correct |
335 ms |
59992 KB |
Output is correct |
38 |
Correct |
1529 ms |
58316 KB |
Output is correct |
39 |
Correct |
1588 ms |
58364 KB |
Output is correct |
40 |
Correct |
1523 ms |
58860 KB |
Output is correct |
41 |
Correct |
673 ms |
47952 KB |
Output is correct |
42 |
Correct |
645 ms |
48012 KB |
Output is correct |
43 |
Correct |
670 ms |
47988 KB |
Output is correct |
44 |
Correct |
651 ms |
48004 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
27228 KB |
Output is correct |
2 |
Correct |
5 ms |
27228 KB |
Output is correct |
3 |
Correct |
5 ms |
27228 KB |
Output is correct |
4 |
Correct |
5 ms |
27228 KB |
Output is correct |
5 |
Correct |
6 ms |
27228 KB |
Output is correct |
6 |
Correct |
5 ms |
27228 KB |
Output is correct |
7 |
Correct |
5 ms |
27228 KB |
Output is correct |
8 |
Correct |
5 ms |
27228 KB |
Output is correct |
9 |
Correct |
6 ms |
27224 KB |
Output is correct |
10 |
Correct |
6 ms |
27228 KB |
Output is correct |
11 |
Correct |
6 ms |
27228 KB |
Output is correct |
12 |
Correct |
6 ms |
27224 KB |
Output is correct |
13 |
Correct |
6 ms |
27228 KB |
Output is correct |
14 |
Correct |
6 ms |
27228 KB |
Output is correct |
15 |
Correct |
6 ms |
27228 KB |
Output is correct |
16 |
Correct |
6 ms |
27284 KB |
Output is correct |
17 |
Correct |
388 ms |
50392 KB |
Output is correct |
18 |
Correct |
380 ms |
50064 KB |
Output is correct |
19 |
Correct |
378 ms |
50000 KB |
Output is correct |
20 |
Correct |
384 ms |
50052 KB |
Output is correct |
21 |
Correct |
409 ms |
50180 KB |
Output is correct |
22 |
Correct |
382 ms |
50260 KB |
Output is correct |
23 |
Correct |
379 ms |
50256 KB |
Output is correct |
24 |
Correct |
413 ms |
50440 KB |
Output is correct |
25 |
Correct |
401 ms |
50552 KB |
Output is correct |
26 |
Correct |
430 ms |
50512 KB |
Output is correct |
27 |
Correct |
349 ms |
50064 KB |
Output is correct |
28 |
Correct |
370 ms |
50444 KB |
Output is correct |
29 |
Correct |
404 ms |
50156 KB |
Output is correct |
30 |
Correct |
384 ms |
50180 KB |
Output is correct |
31 |
Correct |
357 ms |
50172 KB |
Output is correct |
32 |
Correct |
410 ms |
50284 KB |
Output is correct |
33 |
Correct |
1731 ms |
58296 KB |
Output is correct |
34 |
Correct |
636 ms |
47960 KB |
Output is correct |
35 |
Correct |
983 ms |
55600 KB |
Output is correct |
36 |
Correct |
922 ms |
55636 KB |
Output is correct |
37 |
Correct |
912 ms |
55576 KB |
Output is correct |
38 |
Correct |
971 ms |
55548 KB |
Output is correct |
39 |
Correct |
959 ms |
55892 KB |
Output is correct |
40 |
Correct |
1018 ms |
55788 KB |
Output is correct |
41 |
Correct |
935 ms |
55836 KB |
Output is correct |
42 |
Correct |
1028 ms |
56148 KB |
Output is correct |
43 |
Correct |
924 ms |
55764 KB |
Output is correct |
44 |
Correct |
1692 ms |
58888 KB |
Output is correct |
45 |
Correct |
950 ms |
55728 KB |
Output is correct |
46 |
Correct |
368 ms |
64876 KB |
Output is correct |
47 |
Correct |
341 ms |
65108 KB |
Output is correct |
48 |
Correct |
1710 ms |
58940 KB |
Output is correct |
49 |
Correct |
1613 ms |
58428 KB |
Output is correct |
50 |
Correct |
1643 ms |
58816 KB |
Output is correct |
51 |
Correct |
658 ms |
47944 KB |
Output is correct |
52 |
Correct |
631 ms |
47984 KB |
Output is correct |
53 |
Correct |
668 ms |
47964 KB |
Output is correct |
54 |
Correct |
636 ms |
47952 KB |
Output is correct |
55 |
Correct |
1621 ms |
58864 KB |
Output is correct |
56 |
Correct |
673 ms |
48008 KB |
Output is correct |
57 |
Correct |
843 ms |
55496 KB |
Output is correct |
58 |
Correct |
885 ms |
55532 KB |
Output is correct |
59 |
Correct |
836 ms |
55552 KB |
Output is correct |
60 |
Correct |
817 ms |
55888 KB |
Output is correct |
61 |
Correct |
880 ms |
55692 KB |
Output is correct |
62 |
Correct |
851 ms |
55908 KB |
Output is correct |
63 |
Correct |
870 ms |
55864 KB |
Output is correct |
64 |
Correct |
884 ms |
55512 KB |
Output is correct |
65 |
Correct |
893 ms |
55640 KB |
Output is correct |
66 |
Correct |
1546 ms |
58720 KB |
Output is correct |
67 |
Correct |
898 ms |
55832 KB |
Output is correct |
68 |
Correct |
329 ms |
59532 KB |
Output is correct |
69 |
Correct |
335 ms |
59992 KB |
Output is correct |
70 |
Correct |
1529 ms |
58316 KB |
Output is correct |
71 |
Correct |
1588 ms |
58364 KB |
Output is correct |
72 |
Correct |
1523 ms |
58860 KB |
Output is correct |
73 |
Correct |
673 ms |
47952 KB |
Output is correct |
74 |
Correct |
645 ms |
48012 KB |
Output is correct |
75 |
Correct |
670 ms |
47988 KB |
Output is correct |
76 |
Correct |
651 ms |
48004 KB |
Output is correct |
77 |
Correct |
333 ms |
50236 KB |
Output is correct |
78 |
Correct |
389 ms |
47952 KB |
Output is correct |
79 |
Correct |
258 ms |
55672 KB |
Output is correct |
80 |
Correct |
305 ms |
55428 KB |
Output is correct |
81 |
Correct |
266 ms |
55376 KB |
Output is correct |
82 |
Correct |
256 ms |
55508 KB |
Output is correct |
83 |
Correct |
258 ms |
55808 KB |
Output is correct |
84 |
Correct |
299 ms |
55888 KB |
Output is correct |
85 |
Correct |
290 ms |
55584 KB |
Output is correct |
86 |
Correct |
284 ms |
55600 KB |
Output is correct |
87 |
Correct |
267 ms |
55632 KB |
Output is correct |
88 |
Correct |
309 ms |
49896 KB |
Output is correct |
89 |
Correct |
284 ms |
55768 KB |
Output is correct |
90 |
Correct |
331 ms |
60836 KB |
Output is correct |
91 |
Correct |
338 ms |
60300 KB |
Output is correct |
92 |
Correct |
342 ms |
50108 KB |
Output is correct |
93 |
Correct |
319 ms |
49844 KB |
Output is correct |
94 |
Correct |
342 ms |
49608 KB |
Output is correct |
95 |
Correct |
359 ms |
47852 KB |
Output is correct |
96 |
Correct |
376 ms |
47856 KB |
Output is correct |
97 |
Correct |
386 ms |
47856 KB |
Output is correct |
98 |
Correct |
370 ms |
47700 KB |
Output is correct |