import std.stdio; T[] forwardDifference(T)(T[] s, in int n) pure nothrow @nogc { foreach (immutable i; 0 .. n) s[0 .. $ - i - 1] = s[1 .. $ - i] - s[0 .. $ - i - 1]; return s[0 .. $ - n]; } void main() { immutable A = [90.5, 47, 58, 29, 22, 32, 55, 5, 55, 73.5]; foreach (immutable level; 0 .. A.length) forwardDifference(A.dup, level).writeln; }