Tinna is at a train station in America. There are $n$ cities with $m$ trains $T1,$dots,$Tm$ that

go between cities. Train Ti reads from city departure$[$i$]$ at departure time$[$i$]$ and

arrives in city arrival$[$i$]$ at arrival time$[$i$].$ Many trains can go between the same cities

and can have different travel times. It takes Tinna no time to switch between reading

at the train station, for example. Tinna can come at time $t,$ switch trains and continue

with a train that leaves at time $t.$ Tinna starts her journey at time $t=0.$ The arrival

times in arrival$[$i$]$ and departure times in departure$[$i$]$ are given in "clock hours since

Tinna started the journey." Use Dijkstra's algorithm to find the shortest time it takes

to travel from city $A$ to city $B$ when starting in city $A$ at time $t=0.$

Iterate over all cities $v$

$v.d=$ infinite

A$.$d $=0$

$Q=\{\}$ # Empty priority queue that holds cities and v$.$d values

Iterate over all cities $v$

Q$.$insert$($v$,$ v$.$d$)$

while Q$.$notempty$()$

$v=Q.$extractMin$()$

Iterate over all trains Ti from city $v$

# $($the rest of the algorithm comes here$)$