atcoder#ABC204E. [ABC204E] Rush Hour 2
[ABC204E] Rush Hour 2
Score : points
Problem Statement
The Republic of AtCoder has cities and roads.
The cities are numbered through , and the roads are numbered through . Road connects City and City bidirectionally.
There is a rush hour in the country that peaks at time . If you start going through Road at time , it will take time units to reach the other end. ( denotes the largest integer not exceeding .)
Takahashi is planning to depart City at time or some integer time later and head to City .
Print the earliest time when Takahashi can reach City if he can stay in each city for an integer number of time units. It can be proved that the answer is an integer under the Constraints of this problem.
If City is unreachable, print -1
instead.
Constraints
- All values in input are integers.
Input
Input is given from Standard Input in the following format:
Output
Print an integer representing the earliest time when Takahashi can reach City , or -1
if City is unreachable.
2 1
1 2 2 3
4
We will first stay in City until time . Then, at time , we will start going through Road , which will take time units before reaching City at time .
It is impossible to reach City earlier than time .
2 3
1 2 2 3
1 2 2 1
1 1 1 1
3
There may be multiple roads connecting the same pair of cities, and a road going from a city to the same city.
4 2
1 2 3 4
3 4 5 6
-1
There may be no path from City to City .
6 9
1 1 0 0
1 3 1 2
1 5 2 3
5 2 16 5
2 6 1 10
3 4 3 4
3 5 3 10
5 6 1 100
4 2 0 110
20