JavaScript for Project Euler problems

I am trying to solve Q10 from Project Euler. I am using JavaScript and Sieve of Atkins algorithm to solve the problem. When I run the code on browsers(Safari and开发者_如何学编程 FF) the browsers prompts that the script is unresponsive. Even if I let the script to continue I never got the answer. I know there are threads for the same Project Euler problem.

My questions would be:-

1.How far JavaScript is capable to solve such complex mathematical problems for browsers?

2.Is there any other environment where I can I test my JavaScript programs?

Thank you All.

1. I would have thought as capable as any other - JavaScript implementations have been optimised a lot in recent years thanks to increased used in the web.

2. You can use either node.js or CScript (a command line version of the Windows Script host - this is supplied as part of Windows).

If I remember my implementation of that question (in Python) was significantly slower than I thought it would be. The chances are the slowness is due to your algorithm rather than the language.

The goal of project Euler is to get you thinking, mathematically. Think of brute forcing, and you will be stuck. Here is an implementation of the Sieve of Eratosthenes

function problem10() {

    var i, j, k, l = Math.floor((2000000-1)/2), a = [];
    for (i = 0; i < l; i++) {
        a[i] = true;
    } var m = Math.sqrt(2000000);
    for (i = 0; i <= m; i++) {
        if (a[i]) {
            j = 2 * i + 3;
            k = i + j;
            while (k < l) {
                a[k] = false;
                k += j;
            }
        }
    } var s = 2;
    for (i = 0; i < l; i++) {
        if (a[i]) {
            s += 2 * i + 3;
        }
    }
    return s;

}

var d1 = new Date().getTime();
var answer = problem10();
var d2 = new Date().getTime();

console.log('Answer:' + answer + ' time:' + (d2 - d1));

You can run it on the chrome developer's console (Ctrl + Shift + J). And guess what, it clocks 0.1 second.

function problem10(){

    var a = 0;

    function isPrime(n){
        var i = 2;
        var b = true;
        while(i<=Math.sqrt(n) && b){
            b = n%i===0?false:true;
            i++;
        }
        return n<2?false:b;
    }

    for(i=0;i<2000000;i++){
        if(isPrime(i)){
            a+=i;
        }
    }
    return a;

}

You could try testing your implementation on node.js.

However, I would bet that you have a problem with your code. JavaScript in a modern browser is pretty quick (and generally you should get Project Euler answers very quickly; it's not designed to require high amounts of computing power).