#include<bits/stdc++.h>
#define ll long long
using namespace std;
const int N = 500009;
vector<pair<ll, pair<ll, ll > > > v[N];
vector<ll> T[N];
ll d1[N],dn[N], f[N], g[N],ea[N],eb[N],ec[N], par[N],path[N],wh[N];
multiset<pair<ll,ll> > S;
void ad(ll x){
g[x] = 1;
for(auto E : v[x]){
ll y = E.first, l = E.second.first, u= E.second.second;
auto it= S.find({dn[y] + l + d1[x], u});
if(g[y] == 1 && it != S.end()) S.erase(it);
if(g[y] == 0) S.insert({dn[x] + l + d1[y], u});
}
}
ll A = 0;
main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
ll n, m;
cin >> n >> m;
for(ll i = 0; i < m; i++){
cin>>ea[i]>>eb[i]>>ec[i];
}
for(ll i = m-1; i >= 0; i--){
ll a = ea[i], b = eb[i], c = ec[i];
if(a == b)cout<<1/0;
v[a].push_back({b, {c,A}});
v[b].push_back({a, {c,A}});
A = max(A, c);
}
for(ll i = 1; i <= n; i++){
d1[i] = 1e18;
dn[i] = 1e18;
}
d1[1] = 0;
dn[n] = 0;
priority_queue<pair<ll, ll> > q;
q.push({0, 1});
while(q.size()){
ll x = q.top().second;
q.pop();
if(f[x]) continue;
f[x] = 1;
for(auto E: v[x]){
ll y = E.first, l = E.second.first;
if(!f[y] && d1[y] > d1[x] + l){
d1[y] = d1[x] + l;
par[y] = x;
q.push({-d1[y], y});
}
}
}
q.push({0, n});
for(ll i = 1; i <= n; i++)
f[i] = 0;
while(q.size()){
ll x = q.top().second;
q.pop();
if(f[x]) continue;
f[x] = 1;
for(auto E: v[x]){
ll y = E.first, l = E.second.first;
if(!f[y] && dn[y] > dn[x] + l){
dn[y] = dn[x] + l;
q.push({-dn[y], y});
}
}
}
vector<pair<ll,ll> > W;
ll ans = d1[n];
ll X = n;
while(1){
path[X] = 1;
if(X == 1) break;
X = par[X];
}
for(ll i = 1; i <= n; i++){
W.push_back({d1[i], i});
}
sort(W.begin(), W.end());
for(ll i = 0; i < W.size(); i++){
ll x = W[i].second;
if(path[x]) wh[x] = x;
else wh[x] = wh[par[x]];
T[wh[x]].push_back(x);
}
ll x = n;
while(1){
for(ll y : T[x])
ad(y);
if(x == 1) break;
x = par[x];
if(S.size() == 0) continue;
ll U = S.begin()->first + S.begin()->second;
auto it = S.begin();
it++;
if(it != S.end()) U = min(U, it->first);
ans = max(ans, U);
}
cout<<ans<<endl;
}
Compilation message
Aesthetic.cpp:19:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
19 | main(){
| ^
Aesthetic.cpp: In function 'int main()':
Aesthetic.cpp:29:26: warning: division by zero [-Wdiv-by-zero]
29 | if(a == b)cout<<1/0;
| ~^~
Aesthetic.cpp:86:21: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int>, std::allocator<std::pair<long long int, long long int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
86 | for(ll i = 0; i < W.size(); i++){
| ~~^~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
17 ms |
23936 KB |
Output is correct |
2 |
Correct |
17 ms |
23936 KB |
Output is correct |
3 |
Correct |
16 ms |
23936 KB |
Output is correct |
4 |
Correct |
18 ms |
23936 KB |
Output is correct |
5 |
Correct |
16 ms |
23936 KB |
Output is correct |
6 |
Correct |
16 ms |
23936 KB |
Output is correct |
7 |
Correct |
16 ms |
23936 KB |
Output is correct |
8 |
Correct |
17 ms |
23936 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
17 ms |
23936 KB |
Output is correct |
2 |
Correct |
17 ms |
23936 KB |
Output is correct |
3 |
Correct |
16 ms |
23936 KB |
Output is correct |
4 |
Correct |
18 ms |
23936 KB |
Output is correct |
5 |
Correct |
16 ms |
23936 KB |
Output is correct |
6 |
Correct |
16 ms |
23936 KB |
Output is correct |
7 |
Correct |
16 ms |
23936 KB |
Output is correct |
8 |
Correct |
17 ms |
23936 KB |
Output is correct |
9 |
Correct |
19 ms |
24320 KB |
Output is correct |
10 |
Correct |
18 ms |
24184 KB |
Output is correct |
11 |
Correct |
18 ms |
24192 KB |
Output is correct |
12 |
Correct |
19 ms |
24320 KB |
Output is correct |
13 |
Correct |
19 ms |
24320 KB |
Output is correct |
14 |
Correct |
18 ms |
24192 KB |
Output is correct |
15 |
Correct |
18 ms |
24192 KB |
Output is correct |
16 |
Correct |
18 ms |
24184 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
747 ms |
74932 KB |
Output is correct |
2 |
Correct |
800 ms |
79196 KB |
Output is correct |
3 |
Correct |
721 ms |
77796 KB |
Output is correct |
4 |
Correct |
744 ms |
79324 KB |
Output is correct |
5 |
Correct |
733 ms |
78036 KB |
Output is correct |
6 |
Correct |
772 ms |
80608 KB |
Output is correct |
7 |
Correct |
743 ms |
80208 KB |
Output is correct |
8 |
Correct |
758 ms |
79440 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
763 ms |
75228 KB |
Output is correct |
2 |
Correct |
733 ms |
79716 KB |
Output is correct |
3 |
Correct |
736 ms |
78416 KB |
Output is correct |
4 |
Correct |
776 ms |
81088 KB |
Output is correct |
5 |
Correct |
764 ms |
80092 KB |
Output is correct |
6 |
Correct |
787 ms |
81232 KB |
Output is correct |
7 |
Correct |
825 ms |
79824 KB |
Output is correct |
8 |
Correct |
728 ms |
79312 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
134 ms |
63948 KB |
Execution killed with signal 4 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
134 ms |
63948 KB |
Execution killed with signal 4 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
17 ms |
23936 KB |
Output is correct |
2 |
Correct |
17 ms |
23936 KB |
Output is correct |
3 |
Correct |
16 ms |
23936 KB |
Output is correct |
4 |
Correct |
18 ms |
23936 KB |
Output is correct |
5 |
Correct |
16 ms |
23936 KB |
Output is correct |
6 |
Correct |
16 ms |
23936 KB |
Output is correct |
7 |
Correct |
16 ms |
23936 KB |
Output is correct |
8 |
Correct |
17 ms |
23936 KB |
Output is correct |
9 |
Correct |
19 ms |
24320 KB |
Output is correct |
10 |
Correct |
18 ms |
24184 KB |
Output is correct |
11 |
Correct |
18 ms |
24192 KB |
Output is correct |
12 |
Correct |
19 ms |
24320 KB |
Output is correct |
13 |
Correct |
19 ms |
24320 KB |
Output is correct |
14 |
Correct |
18 ms |
24192 KB |
Output is correct |
15 |
Correct |
18 ms |
24192 KB |
Output is correct |
16 |
Correct |
18 ms |
24184 KB |
Output is correct |
17 |
Correct |
747 ms |
74932 KB |
Output is correct |
18 |
Correct |
800 ms |
79196 KB |
Output is correct |
19 |
Correct |
721 ms |
77796 KB |
Output is correct |
20 |
Correct |
744 ms |
79324 KB |
Output is correct |
21 |
Correct |
733 ms |
78036 KB |
Output is correct |
22 |
Correct |
772 ms |
80608 KB |
Output is correct |
23 |
Correct |
743 ms |
80208 KB |
Output is correct |
24 |
Correct |
758 ms |
79440 KB |
Output is correct |
25 |
Correct |
763 ms |
75228 KB |
Output is correct |
26 |
Correct |
733 ms |
79716 KB |
Output is correct |
27 |
Correct |
736 ms |
78416 KB |
Output is correct |
28 |
Correct |
776 ms |
81088 KB |
Output is correct |
29 |
Correct |
764 ms |
80092 KB |
Output is correct |
30 |
Correct |
787 ms |
81232 KB |
Output is correct |
31 |
Correct |
825 ms |
79824 KB |
Output is correct |
32 |
Correct |
728 ms |
79312 KB |
Output is correct |
33 |
Runtime error |
134 ms |
63948 KB |
Execution killed with signal 4 |
34 |
Halted |
0 ms |
0 KB |
- |