I've seen a discussion that
gave a Hash Function .... as this:    x& 2^31
but As the writer say..the tests are too weak..got AC
Is there  any better Hash?...like ELF in string Hash..
touch me Please.

Edited by author 21.10.2010 13:37

Why does my program always get WA#1?
I have tried all the tests in the forum, and all of them are correct.
I think there is a very strange mistake in my program.

#include <stdio.h>
#define re(i, n) for (int i=0; i<n; i++)
#define rre(i, n) for (int i=n-1; i>=0; i--)
const int MAXN = 32;
int b, k;
long long c[MAXN][MAXN], res = 0;
void prp(void)
{
     re(i, MAXN) re(j, MAXN) if (i < j) c[i][j] = 0; else if (!j) c[i][j] = 1; else c[i][j] = c[i - 1][j - 1] * i / j;
}
long long xxx(long long v)
{
     int a[MAXN], len = 0;
     long long r0 = 0;
     while (v) {a[len++] = v % b; v /= b;}
     int k0 = k;
     rre(i, len) {
        int x = a[i];
        if (x >= 2) {r0 += c[i + 1][k0]; break;}
        if (x) {r0 += c[i][k0]; k0--;}
     }
     return r0;
}
int main(void)
{
    long long s, t;
    scanf("%lld%lld%d%d", &s, &t, &k, &b);
    prp();
    res = xxx(t + 1) - xxx(s);
    printf("%lld\n", res);
    return 0;
}


Edited by author 04.09.2010 20:07

In my pgm there's no '0'...
At least we can print(n-1) :)

Edited by author 21.10.2010 01:16

#include<iostream>
using namespace std;
int main()
{
    int sum=0,a;
    cin>>a;
    sum+=a;
    cin>>a;
    sum+=a;
    cout<<sum<<endl;
    return 0;
}

I can't take a[0..25000000]of boolean; Memore Limit?
Why? This Massive is only max 15 mb

My solution works 5.5 sec on the following test. I believe my computer is faster than yours. So, please add this test and make me lose AC.
10 27
a b
a c
a d
a e
a f
a g
a h
a i
a j
d h
d i
d j
e f
e g
e h
e i
e j
f g
f h
f i
f j
g h
g i
g j
h i
h j
i j
a

It seems someone have suggested to hold a common memory segment for all stacks. Here is my way to solve with some details.

Allocate a large array - a common segment for all stacks, and define the size of a block.
int a[BLOCKS*BLOCK_SIZE];
Each block stores (BLOCK_SIZE-1) cells for the numbers and one cells to link it with the previous block for the stack.

Also it is useful to have a bit map reflecting if a particular block is occupied. Make functions find_free_block and release_block.
Also i was needed a couple of arrays of int[1000].

When the next stack grows above (BLOCK_SIZE-1)*k, the new block is occupied and the stack's memory becomes BLOCK_SIZE*(k+1). On the other hand, when i can release a block after POP i do this for memory reuse.

It was found experimetally at the price of 5 MLE attempts that acceptable parameters are:
BLOCKS = 3200; //number of blocks
BLOCK_SIZE = 50; //integers, not bytes

Apparently, the first 12 tests are complete crap: I passed them using dx instead of dy and hypotenuse length instead of leg length. So the hint is to check your program for stupid mistakes.

Be sure to pass the following testcase:

6
1 10
1 10
1 10
1 10
1 10
6 3
1
4 1

z = fact(z)/(2*pow(log(2),n+1));

if(fmod(z,1)>=0.5) z = floor(z) + 1;
else z = floor(z);


I tried the example test case and got true, but got WA with 1st test case... T_T

WTF test?

Why ??

My best time for most programs is 0.015 at least. I see lots of 0.001s exec time . Can share how to write one ? Even the easiest problem A+B

Can someone give me test 6?

For example:
7 10
1 2
2 3
2 4
2 5
3 5
4 5
5 6
5 7
6 7
1 7
At first the DFS procedure find the loop:
(1,2,3,5,6,7,1),then it'll find (1,2,3,5,7,1).
and next,no loop with unused edge will be found!?!
In fact,the maximum T is 3(it's obvious),but use greedy
method + DFS the number of T only reach 2.
Unless we regulated the order of search
(it means DFS can't be right!),otherwise we have to
delete a found loop to let more loop to have unused
edge,then how to make the regulations?

Hello, i try send my programm but always get some WA. Can you explaint few things.
First:
In END of input ".?!"? When i added check for it i get 1WA.
Second:
"ssss[S]ssss" r there mistake? When i check for it i get 2WA
Third:
When i delete this conditions i get 10WA.
Im confused. I've readed all threads and added conditions for every case which i found. What in 10 test?