913 - Joana and the Odd Numbers

sakhassan · Post by **sakhassan** » Sun Oct 08, 2006 10:06 pm

Do i need to precalculate??
how i determine the 1st integer of the line N ????

Jan · Post by **Jan** » Sun Oct 08, 2006 11:00 pm

No need to precalculate anything. You can find a general formula to find the last integer in the line N. First list all the numbers -

Line 1 - 1
Line 3 - 7
Line 5 - 17
Line 7 - 31
Line 9 - 49
Line 11 - 71
...
Line N - ?

The formula is not so tough. Try it.

sakhassan · Post by **sakhassan** » Mon Oct 09, 2006 8:56 am

Thanks J@N.... I got the formula

kana · Post by **kana** » Mon Nov 27, 2006 9:15 pm

can anyone tell me whats the wrong with my code?

Jan · Post by **Jan** » Mon Nov 27, 2006 9:34 pm

Try the samples

Input:

Code: Select all

99999999
1000000001

Output:

Code: Select all

14999999999999991
1500000005999999997

Use 'long long' istead of 'long double'. Dont forget to remove your code. And remember that if you want to post a code then paste your code using 'code' from the editor. Hope these help.

Iffat · Post by **Iffat** » Mon Dec 04, 2006 12:05 pm

can anyone expain why i am getting TLE for this code

Code: Select all

CUT

plzzzzzzzzzz help me!!!
thanx

Jan · Post by **Jan** » Mon Dec 04, 2006 12:10 pm

Read the previous posts and run your code with those samples. You will find the reason yourself.

Iffat · Post by **Iffat** » Mon Dec 04, 2006 12:45 pm

thanx for reply..but i am still confused

...i used long long...will u explain my bug plzz?

Jan · Post by **Jan** » Mon Dec 04, 2006 12:54 pm

'long long' is not the problem.

Code: Select all

      while(n!=1) 
      { 
         sum=sum+(n*2); 
         n-=2; 
      }

If the value of 'n' is big, like 1000000001, then you have to use this loop for (1000000001/2) times. Which is too big. Try to figure out the last odd number in a certain line. You dont have to use any loop. You can find a general formula. Then the result can be found in just O(1) time, which means no loop. Hope you can generate the formula.

Iffat · Post by **Iffat** » Mon Dec 04, 2006 1:19 pm

thanx jan i got the formula and got AC

rezaeeEE · Post by **rezaeeEE** » Thu May 24, 2007 8:56 pm

Code: Select all

removed after accept

Jan · Post by **Jan** » Thu May 24, 2007 9:12 pm

functoin pow() returns double, and you are assigning it to a 'long long' variable. So, precision problems can occur easily. Try to get rid of floating point calculations.

rezaeeEE · Post by **rezaeeEE** » Thu May 24, 2007 9:53 pm

thank u very much mr jan.
you are a great helper.

laicc86 · Post by **laicc86** » Thu Oct 25, 2007 1:46 pm

Code: Select all

deleted after AC

i get RE for this...can anyone help me? thx

Jan · Post by **Jan** » Thu Oct 25, 2007 2:07 pm

The input set contains valid cases. So, no need to check n. And the function should be

Code: Select all

long long odd_num(long long num)

Hope these help.

OJ Board

913 - Joana and the Odd Numbers

913 - Joana and the Odd Numbers

913...TLE!!!!

why wa?

thank u