yeah i got my mistake thanks for that.. but i don't understand how 10^8 can be saved in int..as int have range from -32767 to +32768.... and one more thing to ask is that "int PD=1<<n" will be equivalent to 2^N but PD will definitely go out of range of int in that case..atleast in large output case...
On May 14, 7:49 pm, Bharath Raghavendran <[email protected]> wrote: > I found one mistake : If b < PD, you are returning 0. Why is that? > Lets say you have 4 switches, PD = 16. If b = 15, the answer should be ON. > > Other than that, there are many ways you can improve your code. > 1. > dont use double. It will remove accuracy in many places. 10^8 will come > within 4 bytes (usually int suffices this. else use long int). > > 2. > To calculate 2^n, you can use the left shift operator. "int PD = 1<<n" will > put 2^n into PD. > > 3. > To check if b gives reminder PD -1, you don't need to run a loop. You can do > "if (b%PD == PD-1)" > > On 13 May 2010 10:47, Aamir Khan <[email protected]> wrote: > > > > > #include <cmath> > > #include <cstdio> > > #include <iostream> > > using namespace std; > > > #define _CRT_SECURE_NO_WARNINGS > > #define For(i,a,b) for (long i(a),_b(b); i <= _b; ++i) > > > char buf[1024*1024]; > > > bool isEven(long a,long b) > > { bool result=0; > > if(b%2==0) > > result=0; > > else > > { > > double ad=0.00; > > for(int j=0;j<=30;j++) > > { > > if(int(ad)==a) > > { break;} > > ad=ad+1.00; > > } > > long PD=long(pow(2.00,ad)); > > if(b<PD) > > result=0; > > > else > > { > > for(long i=PD;i<=100000000;i+=PD) > > { > > if(b==i-1) > > { > > result=1; > > break; > > } > > } > > } > > } > > return result; > > } > > > int main() { > > freopen("A-large.in", "rt", stdin); > > freopen("output_Snapper_Chain.txt", "wt", stdout); > > > gets(buf); > > long size=atoi(buf); > > > For(test, 1, size) > > { > > // cout<<"No. of loops"<<test; > > long N; > > long K; > > > scanf("%d%d", &N, &K); > > // cout<<"N"<<N<<"K"<<K; > > > bool res=isEven(N,K); > > if(res) > > printf("Case #%d: ON\n", test); > > else > > printf("Case #%d: OFF\n", test); > > } > > exit(0); > > } > > > --------------------------------------------------------------------------------------------------------------------------- > > SNAPPER CHAIN: > > Can anybody tell me the errors in the code.....i have done this > > problem using the simple concept which i know....it is not giving > > right output.... > > > Brief explanation of code: > > i have first converted the long taken from file into the double using > > for loop..then using pow function i have found 2^N and then found > > whether k==2^N-1; > > > _____ > > Aamir > > > -- > > You received this message because you are subscribed to the Google Groups > > "google-codejam" group.> To post to this group, send email > > [email protected]. > > To unsubscribe from this group, send email > > to>[email protected]<google-code%[email protected]> > > . > > For more options, visit this group at > >http://groups.google.com/group/google-code?hl=en. > > -- > You received this message because you are subscribed to the Google Groups > "google-codejam" group.To post to this group, send email > [email protected] unsubscribe from this group, send email > [email protected]. > For more options, visit this group > athttp://groups.google.com/group/google-code?hl=en. -- You received this message because you are subscribed to the Google Groups "google-codejam" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-code?hl=en.
