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Don't panic when calculating multinomial

This commit is contained in:
Vinzent Steinberg 2017-03-20 09:43:01 +01:00
parent c408bd6605
commit 3de345f912
1 changed files with 1 additions and 3 deletions
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4
integer/src/lib.rs
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@ -697,12 +697,9 @@ pub fn binomial<T: Integer + Clone>(mut n: T, k: T) -> T {
} }
/// Calculate the multinomial coefficient. /// Calculate the multinomial coefficient.
///
/// Panics if no integers are specified.
pub fn multinomial<T: Integer + Clone>(k: &[T]) -> T pub fn multinomial<T: Integer + Clone>(k: &[T]) -> T
where for<'a> T: Add<&'a T, Output = T> where for<'a> T: Add<&'a T, Output = T>
{ {
assert!(k.len() > 0, "need at least one integer");
let mut r = T::one(); let mut r = T::one();
let mut p = T::zero(); let mut p = T::zero();
for i in k { for i in k {
@ -865,6 +862,7 @@ fn test_multinomial() {
check_multinomial!(i64, &[2, 1, 2], 30); check_multinomial!(i64, &[2, 1, 2], 30);
check_multinomial!(i64, &[2, 3, 0], 10); check_multinomial!(i64, &[2, 3, 0], 10);
check_multinomial!(u64, &[], 1);
check_multinomial!(u64, &[0], 1); check_multinomial!(u64, &[0], 1);
check_multinomial!(u64, &[12345], 1); check_multinomial!(u64, &[12345], 1);
} }