/* package whatever; // don't place package name! */
import java.util.*;
import java.lang.*;
import java.io.*;
import java.math.*;
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
{
System.
out.
println(getCollisionProbability
(23,
365)); }
static BigDecimal getCollisionProbability
(int n,
int p
){ return (new BigDecimal("1")).
subtract(fact
(p
).
divide((new BigDecimal(String.
valueOf(p
))).
pow(n
).
multiply(fact
(p
-n
)),
6, RoundingMode.
HALF_UP)); }
}
}
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