Sum of primes between given range

Question

Write the shortest code for finding the sum of primes between a and b (inclusive).

Input

1. a and b can be taken from command line or stdin (space seperated)
2. Assume 1 <= a <= b <= 10⁸

Output Just print the sum with a newline character.

Bonus Points

1. If the program accepts multiple ranges (print one sum on each line), you get extra points. :)

Answer 1

J (41 32 chars):

h=:3 :'+/p:i.(_1 p:>:y)'
f=:-&h<:

eg:

100 f 1
1060

Answer 2

Mathematica 7 (31 chars in plain text)

If PARI/GP solution allowed, then:

Plus@@Select[Range[a,b],PrimeQ]

Answer 3

C (117 including NL)

main(a,b,s,j){
s=0,scanf("%d%d",&a,&b);
for(a+=a==1;a<=b;a++)
for(s+=a,j=2;j<a;)
s-=a%j++?0:(j=a);
printf("%d",s);
}

Answer 4

C# (294 characters):

using System;class P{static void Main(){int a=int.Parse(Console.ReadLine()),b=int.Parse(Console.ReadLine());long t=0;for(int i=a;i<=b;i++)if(p(i))t+=i;Console.WriteLine(t);}static bool p(int n){if((n%2<1&&n!=2)||n<2)return 0>1;for(int i=3;i<=Math.Sqrt(n);i+=2)if(n%i==0)return 0>1;return 1>0;}}

Answer 5

C# (183 characters)

using System;class P{static void Main(string[] a){long s=0,i=Math.Max(int.Parse(a[0]),2),j;for(;i<=int.Parse(a[1]);s+=i++)for(j=2;j<i;)if(i%j++==0){s-=i;break;}Console.WriteLine(s);}}

This would be much shorter if it didn't have to check for 1, or if there was a better way to... In a more readable format:

using System;
class P 
{ 
    static void Main(string[] a) 
    { 
        long s = 0,
             i = Math.Max(int.Parse(a[0]),2),
             j;

        for (; i <= int.Parse(a[1]);s+=i++)
            for (j = 2; j < i; )
                if (i % j++ == 0)
                {
                    s -= i;
                    break;
                }

        Console.WriteLine(s); 
    }
}

Answer 6

PARI/GP (44 characters)

sum(x=nextprime(a),precprime(b),x*isprime(x))

Answer 7

Perl, 62 chars

<>=~/\d+/;map$s+=$_*(1x$_)!~/^1$|(^11+)\1+$/,$&..$';print$s,$/

This one uses the prime number regex.

Answer 8

BASH Shell

47 Characters

seq 1 100|factor|awk 'NF==2{s+=$2}END{print s}'

Edit: Just realized the sum overflows and is coerced as a double.

52 50 Characters

Here's a bit longer solution, but handles overflows aswell

seq 1 100|factor|awk NF==2{print\$2}|paste -sd+|bc

Answer 9

Haskell (80)

c=u[2..];u(p:xs)=p:u[x|x<-xs,x`mod`p>0];s a b=(sum.filter(>=a).takeWhile(<=b))c

s 1 100 == 1060

Answer 10

Ruby 1.9, 63 chars

require'prime';p=->a,b{Prime.each(b).select{|x|x>a}.inject(:+)}

Use like this

p[1,100] #=> 1060

Using the Prime class feels like cheating, but since the Mathematica solutions used built-in prime functions...

Answer 11

Common Lisp: (107 chars)

(flet((p(i)(loop for j from 2 below i never (= (mod i j) 0))))(loop for x from(read)to(read)when(p x)sum x))

only works for starting points >= 1

Answer 12

Python 3.1(270 229 205 chars):

from sys import *
p=[]
for i in range(int(argv[1]),int(argv[2])):
 r=True
 for j in range(2,int(argv[2])):
  if i % j == 0and i != j:
   r=False
 if r:
  p.append(i)
sum = 0
for n in p:
 sum+=n
print(sum)

Answer 13

Perl, 103 chars

while(<>){($a,$b)=split/ /;for($a..$b){next if$_==1;for$n(2..$_-1){$_=0if$_%$n==0}$t+=$_;}print"$t\n";}

It'll accept multiple space separated lines and give the answer for each :D

Answer 14

APL (25 characters)

+/((R≥⎕)^~R∊R∘.×R)/R←1↓⍳⎕

This is a modification of a well-known idiom (see this page for an explanation) for generating a list of primes in APL.

Example:

      +/((R≥⎕)^~R∊R∘.×R)/R←1↓⍳⎕
⎕:
      100
⎕:
      1
1060

Answer 15

C# 302

using System;namespace X{class B{static void Main(){long x=long.Parse(Console.ReadLine()),y=long.Parse(Console.ReadLine()),r=0;for(long i=x;i<=y;i++){if(I(i)){r+=i;}}Console.WriteLine(r);}static bool I(long n){bool b=true;if(n==1){b=false;}for(long i=2;i<n;++i){if(n%i==0){b=false;break;}}return b;}}}

Answer 16

Scala: 260

object P extends App{
def c(M:Int)={val p=(false::false::true::List.range(3,M+1).map(_%2!=0)).toArray
for(i<-(3 to M)
if p(i))
{var j=2*i
while(j<M){p(j)=false
j+=i}}
p}
val l=args.map(_.toInt)
val p=c(l(1))
println((l(0)to l(1)).filter(p).map(_.toLong).sum)}

A self-written primes-sieve.

time scala P 3900000 4000000
25811704341

real    0m8.288s
user    0m6.968s
sys 0m0.456s

Answer 17

Python, 129

A little bit of sorcery:

x,y=map(int,input().split())
y+=1
a=range(y)
print sum(i for i in[[i for a[::i]in[([0]*y)[::i]]][0]for i in a[2:]if a[i]]if i>=x)

Answer 18

Python: 110 chars

l,h=map(int,raw_input().split())
print sum(filter(lambda p:p!=1 and all(p%i for i in range(2,p)),range(l,h)))

Answer 19

In Q (95):

d:{sum s:{if[2=x;:x];if[1=x;:0];$[0=x mod 2;0;0=min x mod 2+til floor sqrt x;0;x]}each x+til y}

Sample Usage:

q)d[1;100]
1060

Answer 20

Factor -> 98

:: s ( a b -- n )
:: i ( n -- ? )
n 1 - 2 [a,b] [ n swap mod 0 > ] all? ;
a b [a,b] [ i ] filter sum ;

Output:

( scratchpad ) 100 1000 s

--- Data stack:
75067

Answer 21

Mathematica, 27

Predefined a and b:

a~Range~b~Select~PrimeQ//Tr

As a function (also 27):

Tr[Range@##~Select~PrimeQ]&

Answer 22

Normal Task (Python 3): 95 chars

a,b=map(int,input().split())
r=range
print(sum(1%i*all(i%j for j in r(2,i))*i for i in r(a,b+1)))

Bonus Task (Python 3): 119 chars

L=iter(map(int,input().split()))
r=range
for a,b in zip(L,L):print(sum(1%i*all(i%j for j in r(2,i))*i for i in r(a,b+1)))