[C language] summary of methods for solving the greatest common divisor

Catalog

One 、 dried food

Two 、 Some broken thoughts

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One 、 dried food

Method 1 ： Circulation

 #include <stdio.h>
 int main()
 {
     int m=30,n=20;
     while(n!=0)
     {
         int tmp=m%n;
         m=n;
         n=tmp;
     }
     printf("%d",m);
     return 0;
 }

Method 2 ： Recursive method 【if-else sentence 】

 #include <stdio.h>
 int gcd(int a,int b);
 int main()
 {
     int m=30,n=20;
     int ret=gcd(m,n);
     printf("%d",ret);
     return 0;
 }
 int gcd(int a,int b)
 {
     if(b==0)
         return a;
     else
         return gcd(b,a%b);
 }

Method 3 ： Recursive simplified version 【 Ternary operator 】

 #include <stdio.h>
 #include <stdio.h>
 int gcd(int a,int b);
 int main()
 {
     int m=30,n=20;
     int ret=gcd(m,n);
     printf("%d",ret);
     return 0;
 }
 int gcd(int a,int b)
 {
     return b==0?a:gcd(b,a%b);
 }

Two 、 Some broken thoughts

I don't remember , This is the first time to see Euclid / The principle of rolling division . Always read and understand , The problem is worked out , No review , Do it again, forget it, and look at the solution . Have no words for yourself .

I mean , No longer long heart , Here comes the fairy , I can't stop you from repeating the mistakes .

Today happens to be an opportunity 【 Both jobs only involve the solution of the greatest common divisor , The most basic , Can't write 】 Help me recognize some problems in my study now .

Now make the following adjustments ： Monthly 30/31 Carry out phased summary and review . The way ： Basic principles of dictation , And express your ideas in code .

Current pit ：① rounding

                  ② greatest common divisor