#P4255. Civilization: The Game of Beliefs
Civilization: The Game of Beliefs
Civilization: The Game of Beliefs
This game, called Civilization (with a twist), is played on a network of cities and roads. There are n cities (numbered from 1 to n) and m bidirectional roads (numbered from 1 to m). The game involves three types of events:
- Add People: The system adds N people to a given city X and assigns them a belief value C.
- Cut Road: The system severs a road given by its road id.
- Query Probability: The system asks, given a city X, if you select N people from all cities reachable from X (by road connections that have not been cut), what is the probability that all selected people have a belief equal to C? The answer should be computed modulo 19260817.
In a query, let the total number of people in the connected component be S and the number of people with belief C be T. If S
where the binomial coefficient is defined as usual.
Note:
- The input data may contain self-loops and multiple roads between the same pair of cities.
- The same road may be cut more than once; only the first cut is effective.
- Since it is the princess's game, the input size may be large; please optimize your input operations.
- For adding people:
1 X N C
— add N people with belief C to city X. - For cutting a road:
2 X
— cut the road with id X. - For a query:
3 X N C
— from the connected component containing city X, if you randomly choose N people, what is the probability that all of them have belief C?
inputFormat
The input begins with two integers n and m (the number of cities and roads).
The next m lines each contain two integers u and v, indicating that there is a bidirectional road connecting city u and city v. Roads are numbered from 1 to m in the order of appearance.
Then an integer Q is given, representing the number of events.
Each of the following Q lines represents an event in one of the following formats:
outputFormat
For each query event (event type 3), output one line containing a single integer: the required probability computed modulo 19260817.
sample
4 3
1 2
2 3
3 4
5
1 1 10 100
1 2 5 100
3 1 3 100
2 2
3 1 3 100
1
1
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