BCDIV - Chia nhóm
Tác giả: ladpro98
Ngôn ngữ: Pascal
program bcdiv;
uses math;
const fi='';
var n,k:longint;
f:array[0..30,0..30] of int64;
t,tt:longint;
inp:text;
procedure input;
begin
assign(inp,fi);
reset(inp);
readln(inp,t);
end;
procedure dp;
var i,j:longint;
begin
f[0,0]:=1;
for i:=1 to n do
begin
f[i,0]:=0;
f[0,i]:=0;
end;
for i:=1 to n do
for j:=1 to k do
f[i,j]:=j*f[i-1,j]+f[i-1,j-1];
end;
begin
input;
for tt:=1 to t do
begin
readln(inp,n,k);
dp;
writeln(f[n,k]);
end;
end.