Classical algorithm detailed (12) Decomposition factorization

Title: It is well known that any composite (which is more than 1 and itself) can be written in several prime-number multiplication forms, which are called the composite's mass factor. For example, 24=2x2x2x3. The form of multiplying a composite into several prime numbers is called decomposition factorization. For a prime number, his qualitative factor can be defined as itself. Write a program to implement the decomposition factorization.

C + + implementation

1#include <iostream>2 3 using namespacestd;4 5 intIsPrime (intN) {6      for(inti =2; I < n; i++) {7         if(n%i = =0)8             return 0;9     }Ten     return 1; One } A  - intGetprimefactor (intN) {//you can return no value, where 1 indicates an error, and return 1 indicates normal.  -     if(N <2) the         return-1; -     if(IsPrime (n)) { -cout << N <<"\ t"; -         return 1; +     } -     Else { +          for(inti =2; I < n; i++) { A             if(n%i = =0) { atcout << i <<"\ t"; -Getprimefactor (N/i); -                  Break; -             } -         } -     } in     return 1; - } to  + intMainintargcChar*argv[]) { -     intA; theCIN >>A; * Getprimefactor (a); $ GetChar ();Panax Notoginseng GetChar (); -     return 0; the}

Idea: First write a function to determine whether a number is a prime, followed by a recursive method, a number divided by its minimum quality factor after the value is a quality factor decomposition of the value, the problem is the same size reduction, so is a recursive problem, the termination condition is that the number is a prime. It can be printed when it is a prime number or when a minimum quality factor is found.

Classical algorithm detailed (12) Decomposition factorization