input:
6 10
2
2
2
0
10
1

output:
NO

9
9
0 9
9 0
5 4
4 5
0 9
9 0
-5 4
-4 5
9 0

Here is my program
var
 n,k,i,time:longint;

begin
 readln(n,k);
 if k=1 then writeln(n-1)
  else
   begin
    i:=0;time:=0;n:=n-1;
    while n>0 do
     begin
      if i<k then i:=i+1;
      n:=n-i;time:=time+1;
     end;
    writeln(time);
   end;
end.

only 4 cases

Edited by author 05.12.2014 19:38

Edited by author 05.12.2014 19:39

found my mistake. sorry for this post.

Edited by author 05.12.2014 22:16

Edited by author 05.12.2014 22:16

if 2 - try
2
4 0
3 2

if 10-11 - just not use sort. especially bubble one)))

Can't get it. What in this test case.
P.S. finding bridges from e-maxx with deep of recursion.

i had 9 wroung attempts, 10 was AC lol

i tried BFS. but WA in test #1. Can anyone suggest some test cases?
Thanks..

#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
    int i,n,a[155],k=0;
    cin>>n;
    for(i=0;i<n;i++)
        cin>>a[i];
    sort(a,a+n+1);
for(i=0;i<n;i++)
if(a[i]==a[i+3])
k++;
cout<<k;
    return 0;
}

I construct vertical blocks made of bricks. Now, blocks are of height 1,2,3,...n-1. Now, to make these many i need n*(n-1)/2 bricks. But, I have n bricks so I have to remove former minus latter number of bricks, which is n(n-3)/2. Now, the problem can be changed to number of ways of obtaining n(n-3)/2 from numbers 1,2,3,...n-1 while each number can be used only once. If you find the approach to be correct, please tell me how to obtain this number.(I am a newbie in coding..:)).

Let me know please, why i should not think in this way -

i have A ways to make n-1 strip sequences. If i will add red or white strip from the
left side, i have A ways to make n strip sequences.

        R/W + [n-1.....]

But in the same time i can add red or white strip from the right side, and so i'll have another
A ways to make n strip sequences.

        [n-1....] + R/W

So, now i have 2*A ways to make n strip sequences.

What's wrong in this kind of argumentation ?

so what is the trick with the test 13? Here is my code:

public static void main(String[] args) {
            Scanner input = new Scanner(System.in);
            int n = input.nextInt();
            int k = input.nextInt();
            long[] arr = new long[k];
            long first = 20000000000000L;
            int first_location = 0;
            long second = 2000000000000L;
            for (int i = 0; i < k; i++)
                arr[i] = input.nextInt();

            for (int i = 0; i < k; i++)
                if (arr[i] < first)
                {
                    first = arr[i];
                    first_location = i;
                }
            arr[first_location] = 0;

            for (int i = 0; i < k; i++)
                if (arr[i] < second && arr[i] != 0)
                    second = arr[i];
            long answer = first + second - n;
            if (answer > 0)
                System.out.println(answer);
            else System.out.println(0);

    }

var a:array[1..20] of integer;
n,n1:string;
x,k,i,s,code:integer;
begin
read(n);
x:=length(n);
k:=x div 3;
if x mod 3>0 then k:=k+1;
for i:=1 to k do begin
n1:=copy(n,x-3*i+1,3);
val(n1,k,code);
a[i]:=k;
delete(n,x-2*i,3);
end;
k:=x div 3;
if x mod 3>0 then k:=k+1;
if k div 2=0 then begin
a[1]:=-1*a[1];
a[3]:=-1*a[3];
a[5]:=-1*a[5];
a[7]:=-1*a[7];
a[9]:=-1*a[9];
a[11]:=-1*a[11];
a[13]:=-1*a[13];
a[15]:=-1*a[15];
a[17]:=-1*a[17];
end
else begin
a[2]:=-1*a[2];
a[4]:=-1*a[4];
a[6]:=-1*a[6];
a[8]:=-1*a[8];
a[10]:=-1*a[10];
a[12]:=-1*a[12];
a[14]:=-1*a[14];
a[16]:=-1*a[16];
end;
for i:=1 to 17 do
s:=s+a[i];
write(abs(s mod 7));
end.

               TIME     Memory
Suffix array - 0.031 s  534 kb
Z-function   - 0.187 s  132 kb

Edited by author 03.12.2014 15:29

My algo is to check that:
1) all spins done in same side
2) all sides are equal
3) all angles are equal
4) in any comparsions precision equals 0.000001 (I tried many variants of precision but got WA12 in any case)

It's hard for me to find tests in this problem :(
What the hell is 12 test?

Edited by author 04.10.2012 12:13

What is test 4?