博客
关于我
java 牛客:因子个数
阅读量:749 次
发布时间:2019-03-22

本文共 2746 字,大约阅读时间需要 9 分钟。

To solve this problem, we need to determine the number of factors for each given positive integer. The solution involves understanding the prime factorization of a number and using it to compute the total number of factors.

Approach

The approach can be broken down into the following steps:

  • Prime Factorization: Decompose the given number into its prime factors. For example, the number 36 can be decomposed into (2^2 \times 3^2).

  • Exponent Tracking: For each prime factor, determine its exponent in the factorization. For instance, in the case of 36, the exponent of 2 is 2, and the exponent of 3 is also 2.

  • Calculate Factors: The total number of factors of a number can be found by taking the product of each prime factor's exponent incremented by one. For example, using the prime factors of 36, the total number of factors is ((2+1) \times (2+1) = 9).

  • Efficient Looping: Use efficient looping techniques to iterate through potential factors, and stop early when further division isn't possible. This optimization prevents unnecessary computations.

  • Solution Code

    import java.util.Scanner;public class Main {    public static void main(String[] args) {        Scanner scanner = new Scanner(System.in);        while (scanner.hasNextInt()) {            int n = scanner.nextInt();            System.out.println(countFactors(n));        }    }    private static int countFactors(int n) {        if (n <= 1) {            return 1;        }        int factors = 1;        for (int i = 2; i * i <= n; ) {            if (n % i == 0) {                int exponent = 0;                while (n % i == 0) {                    exponent++;                    n /= i;                }                factors *= (exponent + 1);            } else {                i++;            }        }        if (n > 1) {            factors *= 2;        }        return factors;    }}

    Explanation

  • Reading Input: The code reads each integer from the standard input.
  • Handling Special Cases: If the input number is 1, it directly returns 1 as it is the only factor.
  • Prime Factorization Loop: The loop iterates from 2 up to the square root of the number. For each potential factor, it checks if it divides the number. If it does, it counts how many times it divides (the exponent) and then divides the number by this factor until it no longer can.
  • Updating Factors Count: The number of factors is updated by multiplying the product of each exponent incremented by one.
  • Remaining Prime Check: If after processing all factors up to the square root, the remaining number is greater than 1, it means it is a prime factor itself, contributing one more factor.
  • This approach efficiently computes the number of factors for each positive integer, ensuring correct and optimal results.

    转载地址:http://nvewk.baihongyu.com/

    你可能感兴趣的文章
    Objective-C实现非丰富数之和算法(附完整源码)
    查看>>
    Objective-C实现非并行奇偶转置排序算法(附完整源码)
    查看>>
    Objective-C实现高斯消元法(附完整源码)
    查看>>
    Objective-C实现高斯消去法(附完整源码)
    查看>>
    Objective-C实现高斯消除算法(附完整源码)
    查看>>
    Objective-C实现高斯滤波GaussianBlur函数用法(附完整源码)
    查看>>
    Objective-C实现高斯滤波函数(附完整源码)
    查看>>
    Objective-C实现高精度乘法(附完整源码)
    查看>>
    Objective-C实现鸡兔同笼问题(附完整源码)
    查看>>
    Objective-c正确的写法单身
    查看>>
    Objective-C语法之代码块(block)的使用
    查看>>
    Object常用方法
    查看>>
    Objenesis创建类的实例
    查看>>
    OBObjective-c 多线程(锁机制) 解决资源抢夺问题
    查看>>
    OBS studio最新版配置鉴权推流
    查看>>
    Obsidian的使用-ChatGPT4o作答
    查看>>
    Obsidian笔记记录GPT回复的数学公式无缝转化插件Katex to mathjax
    查看>>
    ObsoleteAttribute 可适用于除程序集、模块、参数或返回值以外的所有程序元素。 将元素标记为过时可以通知用户:该元素在产品的未来版本中将被移除。...
    查看>>
    OC Xcode快捷键
    查看>>
    oc 中的.m和.mm文件区别
    查看>>