Wrong Answer Again and Again

Posted by

Jordan 18 Feb 2002 08:33

Sos!I really don't know why i always get this reply!Could anybody

point out my fault or give me some testdata?Thanks

Re: Wrong Answer Again and Again

> Sos!I really don't know why i always get this reply!Could anybody

> point out my fault or give me some testdata?Thanks

Use DP:

M[1] = K;

M[2] = (K-1) * K;

M[K] = (K-1) * ( Mas[K-2] + Mas[K-1] ); k<N;

Answer is M[N] = (K-1)*Mas[N-1]

I didn't understand that formula, but here is my program. It uses a different one.

so, A(i)=is the number of valid numbers where the I-th digit is 0

and,B(i)=is the number of valid numbers where the

I-th digit is IN [1..9]

program timus1009;

const

maxn=20;

type

ta=array[0..maxn]of integer;

var

n,k:integer;

A,B:ta;

i:integer;

begin

while not seekeof do begin

readln(n);

readln(k);

A[1]:=0;

B[1]:=k-1;

for i:=2 to n do

begin

A[i]:=B[i-1];

B[i]:=(k-1)*(A[i-1]+B[i-1]);

end;

writeln(A[n]+B[n]);

end;

end.

Re: I didn't understand that formula, but here is my program. It uses a different one.

:)

this is the same thing :)

if you replace A[i-1] = B[i-2] you will get

B[i] = (k - 1) * (B[i - 2] + B[i - 1])