pub fn build_subsum_tree<T>(a: Vec<T>) -> Vec<T>
Expand description
calc subsum tree
14
/\
5 9
/\ /\
2 3 4 5
use ring_algorithm::build_subsum_tree;
let a = vec![2, 3, 4, 5];
let b = vec![14, 5, 9, 2, 3, 4, 5];
let r = build_subsum_tree::<i32>(a);
assert_eq!(b, r);
let a = vec![2, 3, 4, 5, 6];
let b = vec![20, 14, 6, 5, 9, 6, 0, 2, 3, 4, 5, 6, 0, 0, 0];
let r = build_subsum_tree::<i32>(a);
assert_eq!(b, r);