gcd

1. iterativo
2. 
   
3. long int gcd(long int a, long int b)
4. {
5. long int tmp;
6.  
7. if(b > a)
8. {
9. tmp = a;
10. a = b;
11. b = tmp;
12. }
13.  
14. while(b != 0)
15. {
16. tmp = a;
17. a = b;
18. b = tmp % b;
19. }
20. return a;
21. }

1. int gcd(int a,int b){
2. if(a==0)
3. return b;
4. else if(b==0)
5. return a;
6. else if(a==b)
7. return a;
8. if (a > b)
9. return gcd(a-b, b);
10. return gcd(a, b-a);
11.  
12.  
13. }

1. ll gcd(ll val1,ll val2){
2. while(true){
3. if(val1 == val2) return val1;
4. else if(val1 == 0) return val2;
5. else if(val2 == 0) return val1;
7. if(val1 > val2){
8. val1 = val1 - val2;
9. }
10. else if(val2 > val1){
11. val2 = val2 - val1;
12. }
13. }
14. }

1. ll lcm(ll val1,ll val2){
2. return (val1 * val2) / gcd(val1,val2);
3. }

1. int lcm(int a,int b){
2. return a*b/gcd(a,b);
3.  
4. }

propiedad:

lcm(a, b) = (a * b) / gcd(a, b);

1. int lcm(int a, int b)
2. {
3. int large = max(a, b);
4. int small = min(a, b);
5. for (int i = large; ; i += large)
6. {
7. if (i % small == 0)
8. {
9. return i;
10. }
11. }
12. }

1. static int lcm (int a, int b) {
2. return a / gcd(a, b) * b;
3. }
4. static int gcd(int a, int b) {
5. return b == 0 ? a : gcd(b, a % b);
6. }

1. private static int gcd(int a, int b) {
2. if (a == 0)
3. return b;
4. return gcd(b % a, a);
5. }
6.  
7. private static int lcm(int a, int b) {
8. return (a * b) / gcd(a, b);
9. }

1. public static int findLcm(int a, int b){
2.  
3. if(b%a==0) {
4. return b;
5. }
6. for(int i = 2; i<a; i++) {
7. if ((b*i)%a==0) {
8. return b*i;
9. }
10. }
11.  

creo que me quedo con este

1. public static int gcd(int a, int b){
2.  
3. if (b == 0)
4.  
5. return a;
6.  
7. return gcd(b, a % b);
8.  
9. }
10. public static int lcm(int a,int b){
11. int g=gcd(a,b);
12. return (a*b)/g;
13. }
14. }

1. public static int GCD(int x, int y){
3. int gcd = 1;
5. for(int i = 1; i <= x && i <= y; ++i)
6. {
7. if(x % i==0 && y % i==0)
8. gcd = i;
9. }
10. return gcd;
11. }
13. public static int LCM(int z, int k){
14. return (z*k)/GCD(z,k);
15. }