2014
02-14

# The Cow Lineup

Farmer John’s N cows (1 <= N <= 100,000) are lined up in a row.Each cow is labeled with a number in the range 1…K (1 <= K <=10,000) identifying her breed. For example, a line of 14 cows might have these breeds:

1 5 3 2 5 1 3 4 4 2 5 1 2 3

Farmer John’s acute mathematical mind notices all sorts of properties of number sequences like that above. For instance, he notices that the sequence 3 4 1 3 is a subsequence (not necessarily contiguous) of the sequence of breed IDs above. FJ is curious what is the length of the shortest possible sequence he can construct out of numbers in the range 1..K that is NOT a subsequence of the breed IDs of his cows. Help him solve this problem.

* Line 1: Two integers, N and K

* Lines 2..N+1: Each line contains a single integer that is the breed ID of a cow. Line 2 describes cow 1; line 3 describes cow 2; and so on.

* Line 1: Two integers, N and K

* Lines 2..N+1: Each line contains a single integer that is the breed ID of a cow. Line 2 describes cow 1; line 3 describes cow 2; and so on.

14 5
1
5
3
2
5
1
3
4
4
2
5
1
2
3

3

HintAll the single digit 'sequences' appear. Each of the 25 two digit sequences also appears. Of the three digit sequences, the sequence 2, 2, 4 does not appear.  

1..k每个数字都在这个子序列中出现过一次，并且至少有一个数字只出现过一次。

CODE

program POJ1989;//by_poetshy
const
maxn=100000;
var
a                        :array[1..maxn]of longint;
v                        :array[1..maxn]of boolean;
i,n,k,j                    :longint;
ans                        :longint;

begin
for i:=1 to n do readln(a[i]);
j:=0;
fillchar(v,sizeof(v),0);
for i:=1 to n do
begin
if not v[a[i]] then
begin
v[a[i]]:=true;
inc(j);
end;
if j=k then
begin
fillchar(v,sizeof(v),0);
j:=0;inc(ans);
end;
end;
writeln(ans+1);
end.