I don't know what wrong with my code,please tell me~
#include <stdio.h>
int main() {
int p[607],i=3,j=1,k,ans[100000]={-1},n,m,x;
p[0]=2;
while(i<4482) {
for(k=0;p[k]*p[k]<i;k++)
if(i%p[k]==0) break;
if(p[k]*p[k]>i)
p[j++]=i;
i+=2;
}
j=2;
ans[0]=3;
ans[1]=5;
while(scanf("%d",&n)) {
if(n<j);
else {
i=j;
m=ans[j-1]+6;
x=m+2;
while(j<n) {
for(k=0;p[k]*p[k]<x;k++)
if(m%p[k]==0||x%p[k]==0) break;
if(p[k]*p[k]>x)
ans[j++]=m;
m+=6;
x+=6;
}
}
printf("(%d, %d)\n",ans[n-1],ans[n-1]+2);
}
return 0;
}
10394 - Twin Primes
Moderator: Board moderators
If judge gives your program output limit exceeded. then change
into
and after that you may get answers other the OLE 
Code: Select all
while(scanf("%d",&n)) Code: Select all
while(1==scanf("%d",&n))
-
little joey
- Guru
- Posts: 1080
- Joined: Thu Dec 19, 2002 7:37 pm
10394 compiler error??
This is my code ,it runs well in VC,why i submit it will be compiler error??
[cpp]
#include <iostream>
using namespace std;
int b[20250000]={0};
void prime()
{
long i,j;
b[1]=1;
for(i=1;i<4500;i++)
if (b==0)
for(j=2;j<=20250000/i;j++)
b[i*j]=1;
}
int main()
{
long a[100010];
long cnt=1;
long i,j;
prime();
for(i=2;;i++)
{
if(b==0&&b[i+2]==0)
a[cnt++]=i;
if(cnt>100000)
break;
}
while(cin>>j)
{
cout<<"("<<a[j]<<", "<<a[j]+2<<")"<<endl;
}
return 0;
}
[/cpp]
[cpp]
#include <iostream>
using namespace std;
int b[20250000]={0};
void prime()
{
long i,j;
b[1]=1;
for(i=1;i<4500;i++)
if (b==0)
for(j=2;j<=20250000/i;j++)
b[i*j]=1;
}
int main()
{
long a[100010];
long cnt=1;
long i,j;
prime();
for(i=2;;i++)
{
if(b==0&&b[i+2]==0)
a[cnt++]=i;
if(cnt>100000)
break;
}
while(cin>>j)
{
cout<<"("<<a[j]<<", "<<a[j]+2<<")"<<endl;
}
return 0;
}
[/cpp]
-
little joey
- Guru
- Posts: 1080
- Joined: Thu Dec 19, 2002 7:37 pm
You declare long a[100010] dynamically within function main(). The maximum amount of dyn. memory to be assigned within one function is someting like 64k, much less than the 400k you require.
Make it static.
Now you will probably get a "Memory Limit Exeeded" because your array int b[20250000] is over 80Meg, much more than the allowed 32Meg.
Make it an array of bytes (char or unsigned char). Or better still, pack 8 of them into the bits of a byte.
I'm not sure, but now you'll probably get "Time Limit Exeeded" because your algorithm doesn't look very fast. But I might be wrong. If so, you'll need to optimize it. Your inner loop contains one division and one multiplication. Both can be avoided. And an other thing: Do you realy have to consider even numbers for this problem?
Make it static.
Now you will probably get a "Memory Limit Exeeded" because your array int b[20250000] is over 80Meg, much more than the allowed 32Meg.
Make it an array of bytes (char or unsigned char). Or better still, pack 8 of them into the bits of a byte.
I'm not sure, but now you'll probably get "Time Limit Exeeded" because your algorithm doesn't look very fast. But I might be wrong. If so, you'll need to optimize it. Your inner loop contains one division and one multiplication. Both can be avoided. And an other thing: Do you realy have to consider even numbers for this problem?
-
Fuad Hassan_IIUC(DC)
- New poster
- Posts: 18
- Joined: Fri Jan 07, 2005 9:35 pm
- Location: Bangladesh
10394 WA????
plz help me 
#include<iostream.h>
#include<stdio.h>
#include<math.h>
#define max 100000
long long seive[max];
long long pi;
long long a[max],b[max];
long long prime[max];
void genseive()
{
long i,j,sq;
sq=sqrt(max);
seive[0]=seive[1]=1;
for(i=2;i<=sq;++i)
{
for(j=i+i;j<=max;j+=i)
seive[j]=1;
}
j=-1;pi=0;
for(i=2;i<=max;++i)
{
if(seive==0)
{
prime[++j]=i;
pi++;
}
}
}
int main()
{
genseive();
long long i,j,k,l;
while(cin>>l)
{
j=0;
for(i=0;i<=pi;i++)
{
k=labs(prime-prime[i+1]);
if(k==2)
{
a[j]=prime;
b[j]=prime[i+1];
j++;
}
else continue;
}
printf("(%lld, %lld)",a[l-1],b[l-1]);
printf("\n");
}
return 0;
}
#include<iostream.h>
#include<stdio.h>
#include<math.h>
#define max 100000
long long seive[max];
long long pi;
long long a[max],b[max];
long long prime[max];
void genseive()
{
long i,j,sq;
sq=sqrt(max);
seive[0]=seive[1]=1;
for(i=2;i<=sq;++i)
{
for(j=i+i;j<=max;j+=i)
seive[j]=1;
}
j=-1;pi=0;
for(i=2;i<=max;++i)
{
if(seive==0)
{
prime[++j]=i;
pi++;
}
}
}
int main()
{
genseive();
long long i,j,k,l;
while(cin>>l)
{
j=0;
for(i=0;i<=pi;i++)
{
k=labs(prime-prime[i+1]);
if(k==2)
{
a[j]=prime;
b[j]=prime[i+1];
j++;
}
else continue;
}
printf("(%lld, %lld)",a[l-1],b[l-1]);
printf("\n");
}
return 0;
}
fuad
-
mohiul alam prince
- Experienced poster
- Posts: 120
- Joined: Sat Nov 01, 2003 6:16 am
- Location: Dhaka (EWU)
Hi
There are so many problem's in ur programm.
- First u have to generate 20000000 prime's
- Then u have to store all the primes in a another array
- and Mind it that if (Primes and Primes[i + 2] are prime) then u will only store it
- and then take input and print the Nth twin primes
and ur seive algorithm is not correct.
This is a sample code
MAP
There are so many problem's in ur programm.
- First u have to generate 20000000 prime's
- Then u have to store all the primes in a another array
- and Mind it that if (Primes and Primes[i + 2] are prime) then u will only store it
- and then take input and print the Nth twin primes
and ur seive algorithm is not correct.
This is a sample code
Code: Select all
for ( i = 2; i <= max; i++)seive[i] = 1;
for ( i = 3; i < max; i += 2)
if ( seive[j] )
for ( j = i + i; j < max; j += i )
seive[j] = 0;
10394 runtime error ..
it runs ok on my computer (dev-cpp)
help me...
help me...
Code: Select all
//10394 Twin Primes
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define uns32 unsigned long
#define LONG uns32
#define UL "%u"
#define HALF unsigned short
#define BITS 8
#define LCM (2*3*5)
#define SIEVE_SIZE (16<<10)
#define use(x) if(x-last==2) primes[pairPos++]=last;last=x; anz++;
double sum=0.0;
LONG max=0, last=2;
unsigned char sieve[SIEVE_SIZE];
LONG *index;
LONG totalPrime;
LONG primes[107407];
LONG pairPos=0;
long sievePrimes(LONG stop,LONG start=1,LONG sieveSize=SIEVE_SIZE)
{
uns32 size, hi, h, ji, js, i, j;
uns32 k, hj, c, cj;
unsigned char *prime_diff;
unsigned char bi, b, m;
LONG stlcm, ii, jj, hh, anz;
HALF psize;
int lim;
size=sieveSize;
anz=0;
//j = floor( sqrt((double)stop+0.1) );
//if (!(j&1))
//--j;
j=4471;
//psize = floor((1.015*j)/(log((double)j)-1));
psize=612;
index = (LONG*) malloc((sizeof(LONG)+1)*psize);
prime_diff = (unsigned char*)(index+psize);
use(2);
use(3);
if (start%2 == 0)
start += 1;
if (start%3 == 0)
start += 2;
stlcm = start/LCM;
hh = size*(stlcm/size);
/*** sifting the sieve primes ***/
k=m=0;
h=i=cj=0;
js=jj=0;
b=c=1;
for(;;)
{
switch (c)
{
do
{
case 1:
i++;
if ((m+=1) >= LCM/3)
m -= LCM/3;
////////////
jj += h<<1;
++h;
++jj;
//origin code
//jj+=h;
//h++;
//jj+=h;
if (!(sieve[i]&b))
{
c= 2;
break;
}
case 2:
i++;
if (i == size)
{
i=0;
cj += size;
//b+=b;
b <<= 1;
if (!b)
break;
}
if ((m+=1) >= LCM/3)
m -= LCM/3;
jj += h;
if (!(sieve[i]&b))
{
c= 1;
break;
}
}while (1);
}
if ((jj<<3) > stop/3)
break;
//j = 3*(cj+i)+c;
j=((cj+i)<<1)+cj+i+c;
bi= m - !!m - m/BITS;
prime_diff[k]= BITS*2*(j/LCM-js); /* difference of successive primes < 480 */
prime_diff[k] |= bi;
js= j/LCM;
index[k]= ((bi&1) != (bi>>2&1) ? 5 : 0);
//ii=(8*jj)/(LCM/3);
ii= (jj<<3)/(LCM/3);
if (ii < stlcm)
ii += j*((stlcm-ii)/j);
if (ii < stlcm)
{
hi = (index[k] ? 19 : 1); /* inverse zu index[k] --- 0 <--> 1 Argh!! */
//hj= js+js;
hj=(js<<1);
//ji= 2*(3*m+c);
ji=(((m<<1)+m+c)<<1);
if (ji >= LCM) ji-=LCM, hj++;
switch (c)
{
do
{
case 1:
ii += (hj<<1);
hi += (ji<<1);
while (hi >= LCM)
hi -= LCM, ii++;
if (ii >= stlcm && hi!=5 && hi!=25)
break;
case 2:
ii += hj;
hi += ji;
while (hi >= LCM)
hi -= LCM, ii++;
if (ii >= stlcm && hi!=5 && hi!=25)
break;
} while(1);
}
index[k] = (BITS*hi)/LCM;
}
index[k] |= BITS*(ii-hh);
k++;
if (jj >= size)
continue;
/*** sift with prime pre-sieve ***/
hi = (jj<<3);
ji= ((cj+i)<<1);
++ji;
hj= ((ji+c)<<1)-3;
bi= 1;
switch(m)
{
do
{
case 0:
while(hi >= size)
{
hi -= size;
bi<<=1;
if (!bi)
goto go_on;
}
sieve[hi] |= bi;
hi += (j<<1);
case 2:
while(hi >= size)
{
hi -= size;
bi<<=1;
if (!bi)
goto go_on;
}
sieve[hi] |= bi;
hi += hj;
case 3:
while(hi >= size)
{
hi -= size;
bi<<=1;
if (!bi)
goto go_on;
}
sieve[hi] |= bi;
hi += ji;
case 4:
while(hi >= size)
{
hi -= size;
bi<<=1;
if (!bi)
goto go_on;
}
sieve[hi] |= bi;
hi += hj;
case 5:
while(hi >= size)
{
hi -= size;
bi<<=1;
if (!bi)
goto go_on;
}
sieve[hi] |= bi;
hi += ji;
case 6:
while(hi >= size)
{
hi -= size;
bi<<=1;
if (!bi)
goto go_on;
}
sieve[hi] |= bi;
hi += hj;
case 7:
while(hi >= size)
{
hi -= size;
bi<<=1;
if (!bi)
goto go_on;
}
sieve[hi] |= bi;
hi += (j<<1);
case 9:
while(hi >= size)
{
hi -= size;
bi<<=1;
if (!bi)
goto go_on;
}
sieve[hi] |= bi;
hi += ji;
lim= size - LCM/3*j;
while ((int)hi < lim)
{
sieve[hi] |= bi; hi += (j<<1);
sieve[hi] |= bi; hi += hj;
sieve[hi] |= bi; hi += ji;
sieve[hi] |= bi; hi += hj;
sieve[hi] |= bi; hi += ji;
sieve[hi] |= bi; hi += hj;
sieve[hi] |= bi; hi += (j<<1);
sieve[hi] |= bi; hi += ji;
}
}while (1);
do
{
case 1:
while(hi >= size)
{
hi -= size;
bi<<=1;
if (!bi)
goto go_on;
}
sieve[hi] |= bi;
hi += ji;
case 8:
while(hi >= size)
{
hi -= size;
bi<<=1;
if (!bi)
goto go_on;
}
sieve[hi] |= bi;
hi += hj;
lim= size - LCM/3* 5;
while ((int)hi < lim)
{
sieve[hi] |= bi;
hi += ji;
sieve[hi] |= bi; hi += hj;
sieve[hi] |= bi; hi += ji;
sieve[hi] |= bi; hi += hj;
sieve[hi] |= bi; hi += ji;
sieve[hi] |= bi; hi += hj;
sieve[hi] |= bi; hi += ji;
sieve[hi] |= bi; hi += hj;
sieve[hi] |= bi; hi += ji;
sieve[hi] |= bi; hi += hj;
}
}while (1);
}
go_on: ;
}
/****** main sifting starts *****/
for (i=size;i--;)
sieve[i]=0;
sieve[0] |= !hh; /* 1 is not prime */
if (start <= 5) use(5);
if (start%5 == 0) start += 2*(3-start%3);
hh *= LCM;
while (1)
{
j= prime_diff[0]/BITS;
for (h=1;h<k;h++) /* sieve with next sieve prime (h=0 is prime 5) */
{
j += prime_diff[h]/BITS;
ii = index[h]/BITS;
if (ii >= size)
{
index[h] -= size*BITS;
continue;
}
hj= (size <= LCM/2*j ? 0 : size - LCM/2*j);
i=ji=js= j;
ji +=js;
i += ji;
hi = ii;
switch( prime_diff[h]%BITS )
{
case 0:
switch( index[h]%BITS )
{
do
{
case 0:
if (hi >= size)
goto out0;
sieve[hi] |= 1; hi += i;
case 1:
if (hi >= size)
goto out1;
sieve[hi] |= 2; hi += ji;
case 2:
if (hi >= size)
goto out2;
sieve[hi] |= 4; hi += js;
case 3:
if (hi >= size)
goto out3;
sieve[hi] |= 8; hi += ji;
case 4:
if (hi >= size)
goto out4;
sieve[hi] |= 16; hi += js;
case 5:
if (hi >= size)
goto out5;
sieve[hi] |= 32; hi += ji;
case 6:
if (hi >= size)
goto out6;
sieve[hi] |= 64; hi += i;
case 7:
if (hi >= size)
goto out7;
sieve[hi] |=128; hi += js+1;
lim= hj-1;
while((int)hi < lim)
{
sieve[hi] |= 1; hi += i;
sieve[hi] |= 2; hi += ji;
sieve[hi] |= 4; hi += js;
sieve[hi] |= 8; hi += ji;
sieve[hi] |= 16; hi += js;
sieve[hi] |= 32; hi += ji;
sieve[hi] |= 64; hi += i;
sieve[hi] |=128; hi += js+1;
}
}while (1);
}
case 1:
js+=1; i+=1; ji+=1;
switch( index[h]%BITS )
{
do
{
case 5:
if (hi >= size)
goto out5;
sieve[hi] |= 32; hi += ji;
case 4:
if (hi >= size)
goto out4;
sieve[hi] |= 16; hi += js;
case 0:
if (hi >= size)
goto out0;
sieve[hi] |= 1; hi += ji-1;
case 7:
if (hi >= size)
goto out7;
sieve[hi] |=128; hi += js;
case 3:
if (hi >= size)
goto out3;
sieve[hi] |= 8; hi += ji;
case 2:
if (hi >= size)
goto out2;
sieve[hi] |= 4; hi += i;
case 6:
if (hi >= size)
goto out6;
sieve[hi] |= 64; hi += js;
case 1:
if (hi >= size)
goto out1;
sieve[hi] |= 2; hi += i;
lim= hj-7;
while((int)hi < lim)
{
sieve[hi] |= 32; hi += ji;
sieve[hi] |= 16; hi += js;
sieve[hi] |= 1; hi += ji-1;
sieve[hi] |=128; hi += js;
sieve[hi] |= 8; hi += ji;
sieve[hi] |= 4; hi += i;
sieve[hi] |= 64; hi += js;
sieve[hi] |= 2; hi += i;
}
}while (1);
}
case 2:
i+=2; ji+=2;
switch( index[h]%BITS )
{
do
{
case 0:
if (hi >= size)
goto out0;
sieve[hi] |= 1; hi += js;
case 6:
if (hi >= size)
goto out6;
sieve[hi] |= 64; hi += ji;
case 1:
if (hi >= size)
goto out1;
sieve[hi] |= 2; hi += js;
case 7:
if (hi >= size)
goto out7;
sieve[hi] |=128; hi += ji;
case 3:
if (hi >= size)
goto out3;
sieve[hi] |= 8; hi += i;
case 5:
if (hi >= size)
goto out5;
sieve[hi] |= 32; hi += js+1;
case 2:
if (hi >= size)
goto out2;
sieve[hi] |= 4; hi += i;
case 4:
if (hi >= size)
goto out4;
sieve[hi] |= 16; hi += ji;
lim= hj-11;
while((int)hi < lim)
{
sieve[hi] |= 1; hi += js;
sieve[hi] |= 64; hi += ji;
sieve[hi] |= 2; hi += js;
sieve[hi] |=128; hi += ji;
sieve[hi] |= 8; hi += i;
sieve[hi] |= 32; hi += js+1;
sieve[hi] |= 4; hi += i;
sieve[hi] |= 16; hi += ji;
}
}while (1);
}
case 3:
js+=1; i+=3; ji+=1;
switch( index[h]%BITS )
{
do
{
case 5:
if (hi >= size)
goto out5;
sieve[hi] |= 32; hi += ji+1;
case 2:
if (hi >= size)
goto out2;
sieve[hi] |= 4; hi += js;
case 1:
if (hi >= size)
goto out1;
sieve[hi] |= 2; hi += ji;
case 7:
if (hi >= size)
goto out7;
sieve[hi] |=128; hi += i;
case 4:
if (hi >= size)
goto out4;
sieve[hi] |= 16; hi += js;
case 3:
if (hi >= size)
goto out3;
sieve[hi] |= 8; hi += i;
case 0:
if (hi >= size)
goto out0;
sieve[hi] |= 1; hi += ji;
case 6:
if (hi >= size)
goto out6;
sieve[hi] |= 64; hi += js;
lim= hj-13;
while((int)hi < lim)
{
sieve[hi] |= 32; hi += ji+1;
sieve[hi] |= 4; hi += js;
sieve[hi] |= 2; hi += ji;
sieve[hi] |=128; hi += i;
sieve[hi] |= 16; hi += js;
sieve[hi] |= 8; hi += i;
sieve[hi] |= 1; hi += ji;
sieve[hi] |= 64; hi += js;
}
}while (1);
}
case 4:
js+=1; i+=3; ji+=3;
switch( index[h]%BITS )
{
do
{
case 5:
if (hi >= size)
goto out5;
sieve[hi] |= 32; hi += js;
case 6:
if (hi >= size)
goto out6;
sieve[hi] |= 64; hi += ji;
case 0:
if (hi >= size)
goto out0;
sieve[hi] |= 1; hi += i;
case 3:
if (hi >= size)
goto out3;
sieve[hi] |= 8; hi += js;
case 4:
if (hi >= size)
goto out4;
sieve[hi] |= 16; hi += i;
case 7:
if (hi >= size)
goto out7;
sieve[hi] |=128; hi += ji;
case 1:
if (hi >= size)
goto out1;
sieve[hi] |= 2; hi += js;
case 2:
if (hi >= size)
goto out2;
sieve[hi] |= 4; hi += ji-1;
lim= hj-17;
while((int)hi < lim)
{
sieve[hi] |= 32; hi += js;
sieve[hi] |= 64; hi += ji;
sieve[hi] |= 1; hi += i;
sieve[hi] |= 8; hi += js;
sieve[hi] |= 16; hi += i;
sieve[hi] |=128; hi += ji;
sieve[hi] |= 2; hi += js;
sieve[hi] |= 4; hi += ji-1;
}
}while (1);
}
case 5:
js+=2; i+=4; ji+=2;
switch( index[h]%BITS )
{
do
{
case 0:
if (hi >= size)
goto out0;
sieve[hi] |= 1; hi += ji;
case 4:
if (hi >= size)
goto out4;
sieve[hi] |= 16; hi += i;
case 2:
if (hi >= size)
goto out2;
sieve[hi] |= 4; hi += js-1;
case 5:
if (hi >= size)
goto out5;
sieve[hi] |= 32; hi += i;
case 3:
if (hi >= size)
goto out3;
sieve[hi] |= 8; hi += ji;
case 7:
if (hi >= size)
goto out7;
sieve[hi] |=128; hi += js;
case 1:
if (hi >= size)
goto out1;
sieve[hi] |= 2; hi += ji;
case 6:
if (hi >= size)
goto out6;
sieve[hi] |= 64; hi += js;
lim= hj-19;
while((int)hi < lim)
{
sieve[hi] |= 1; hi += ji;
sieve[hi] |= 16; hi += i;
sieve[hi] |= 4; hi += js-1;
sieve[hi] |= 32; hi += i;
sieve[hi] |= 8; hi += ji;
sieve[hi] |=128; hi += js;
sieve[hi] |= 2; hi += ji;
sieve[hi] |= 64; hi += js;
}
}while (1);
}
case 6:
js+=1; i+=5; ji+=3;
switch( index[h]%BITS )
{
do
{
case 5:
if (hi >= size)
goto out5;
sieve[hi] |= 32; hi += i;
case 1:
if (hi >= size)
goto out1;
sieve[hi] |= 2; hi += js;
case 6:
if (hi >= size)
goto out6;
sieve[hi] |= 64; hi += i;
case 2:
if (hi >= size)
goto out2;
sieve[hi] |= 4; hi += ji;
case 3:
if (hi >= size)
goto out3;
sieve[hi] |= 8; hi += js;
case 7:
if (hi >= size)
goto out7;
sieve[hi] |=128; hi += ji+1;
case 0:
if (hi >= size)
goto out0;
sieve[hi] |= 1; hi += js;
case 4:
if (hi >= size)
goto out4;
sieve[hi] |= 16; hi += ji;
lim= hj-23;
while((int)hi < lim)
{
sieve[hi] |= 32; hi += i;
sieve[hi] |= 2; hi += js;
sieve[hi] |= 64; hi += i;
sieve[hi] |= 4; hi += ji;
sieve[hi] |= 8; hi += js;
sieve[hi] |=128; hi += ji+1;
sieve[hi] |= 1; hi += js;
sieve[hi] |= 16; hi += ji;
}
}while (1);
}
case 7:
js+=2; i+=6; ji+=4;
switch( index[h]%BITS )
{
do
{
case 0:
if (hi >= size)
goto out0;
sieve[hi] |= 1; hi += js-1;
case 7:
if (hi >= size)
goto out7;
sieve[hi] |=128; hi += i;
case 6:
if (hi >= size)
goto out6;
sieve[hi] |= 64; hi += ji;
case 5:
if (hi >= size)
goto out5;
sieve[hi] |= 32; hi += js;
case 4:
if (hi >= size)
goto out4;
sieve[hi] |= 16; hi += ji;
case 3:
if (hi >= size)
goto out3;
sieve[hi] |= 8; hi += js;
case 2:
if (hi >= size)
goto out2;
sieve[hi] |= 4; hi += ji;
case 1:
if (hi >= size)
goto out1;
sieve[hi] |= 2; hi += i;
lim= hj-29;
while ((int)hi < lim)
{
sieve[hi] |= 1; hi += js-1;
sieve[hi] |=128; hi += i;
sieve[hi] |= 64; hi += ji;
sieve[hi] |= 32; hi += js;
sieve[hi] |= 16; hi += ji;
sieve[hi] |= 8; hi += js;
sieve[hi] |= 4; hi += ji;
sieve[hi] |= 2; hi += i;
}
}while (1);
}
}
out0: index[h] = 0;
goto out;
out1: index[h] = 1;
goto out;
out2: index[h] = 2;
goto out;
out3: index[h] = 3;
goto out;
out4: index[h] = 4;
goto out;
out5: index[h] = 5;
goto out;
out6: index[h] = 6;
goto out;
out7: index[h] = 7;
goto out;
out:
hi -= size;
index[h] |= BITS*hi;
}
/*** output of remaining (prime) numbers ***/
i=(start<=hh ? 0 : (start-hh)/LCM);
hh += LCM*i;
bi= sieve[i];
switch (start<=hh ? 0 : (BITS*(unsigned)(start-hh))/LCM)
{
for (;i<size;i++)
{
bi= sieve[i];
case 0:
if (!(bi&1))
{
ii= hh+1;
if (ii > stop)
goto end;
use(ii);
}
case 1:
if (!(bi&2))
{
ii= hh+7;
if (ii > stop)
goto end;
use(ii);
}
case 2:
if (!(bi&4))
{
ii= hh+11;
if (ii > stop)
goto end;
use(ii);
}
case 3:
if (!(bi&8))
{
ii= hh+13;
if (ii > stop)
goto end;
use(ii);
}
case 4:
if (!(bi&16))
{
ii= hh+17;
if (ii > stop)
goto end;
use(ii);
}
case 5:
if (!(bi&32))
{
ii= hh+19;
if (ii > stop)
goto end;
use(ii);
}
case 6:
if (!(bi&64))
{
ii= hh+23;
if (ii > stop)
goto end;
use(ii);
}
case 7:
if (!(bi&128))
{
ii= hh+29;
if (ii > stop)
goto end;
use(ii);
}
hh += LCM;
sieve[i]=0;
}
}
}
end:
free(index);
free(sieve);
finish:
//printf("# {"UL" <= primes <= "UL"} = "UL"\n",start,stop,anz);
//printf("time used for sieving primes: %.3f\n",(clock()-beg)/1000.0);
return anz;
}
int main(int argc,char *argv[])
{
sievePrimes(20000000,1);
long p;
while(scanf("%ld",&p)==1)
{
printf("(%ld, %ld)\n",primes[p-1],primes[p-1]+2);
}
}
*) It's high time you rethink your algorithm
*) Dont use UL as a macro, it clashes with specifiers for integer literals
i.e.
is valid C and instantiates x as an unsigned long whose bit pattern represents the decimal value 32.
Regards,
Suman.
*) Dont use UL as a macro, it clashes with specifiers for integer literals
i.e.
Code: Select all
unsigned long int x = 32UL;
Regards,
Suman.