求素数两种方法方法2牛逼-CFANZ编程社区

求素数两种方法方法2牛逼

weednoah 2022-03-30 阅读 42

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>素数</title>
    <script>
        //方法1
        let data1 = +new Date();
        let a = 0;
        let arr = [];
        for (i = 2; i < 100; i++) {
            let k = 0;
            for (j = 2; j < 100; j++) {
                if (i % j == 0) {
                    k++;
                    // 因为素数的因数只有1和它本身，故k值为1就是素数
                }
                a++;
                if (i < j || k > 1) {
                    break;
                }
            }
            if (k == 1) {
                document.write(i + ", ");
                arr.push(i);
            }
        }

        let sum1 = arr.reduce((last, item) => {
            return last + item
        }, 0)
        let data2 = +new Date();
        console.log(a, sum1, arr, '=======');
        //方法2
        var sum = 0;
        let b = 0;
        let arr2 = [];
        for (var i = 2; i <= 2000; i++) {
            let m = 1;
            for (var j = 2; j <= Math.sqrt(i); j++) {
                if (i % j == 0) {
                    m = 0;
                    break;
                }
                b++;
            }

            if (m == 1) {
                arr2.push(i);
                sum += i;
            }
        }
        let data3 = +new Date();

        console.log(b, sum, arr2, '-----');

        console.log(data2 - data1, data3 - data2);
    </script>
</head>

<body>

</body>

</html>

0 条评论