blocks|key|2001096|text|对于int和long，作为原语，并不是真的。对于Integer，可能有人写了一个。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2001097|假设BigInteger是int、Integer、long和Long的(数学/函数)超集，如果需要使用这些类型，请将它们转换为BigInteger，执行GCD，然后再将结果转换回来。|2001098|private+static+int+gcdThing(int+a,+int+b)+{
++++BigInteger+b1+=+BigInteger.valueOf(a);
++++BigInteger+b2+=+BigInteger.valueOf(b);
++++BigInteger+gcd+=+b1.gcd(b2);
++++return+gcd.intValue();
}|code-block|syntax|javascript|2001099|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

For int and long, as primitives, not really. For Integer, it is possible someone wrote one.

Given that BigInteger is a (mathematical/functional) superset of int, Integer, long, and Long, if you need to use these types, convert them to a BigInteger, do the GCD, and convert the result back.

<pre><code>private static int gcdThing(int a, int b) {
 BigInteger b1 = BigInteger.valueOf(a);
 BigInteger b2 = BigInteger.valueOf(b);
 BigInteger gcd = b1.gcd(b2);
 return gcd.intValue();
}
</code></pre>

blocks|key|1787457|text|据我所知，没有任何原语的内置方法。但是，像这样简单的东西应该能起到作用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1787458|public+int+gcd(int+a,+int+b)+{
+++if+(b==0)+return+a;
+++return+gcd(b,a%25b);
}|code-block|syntax|javascript|1787459|如果你对这类东西感兴趣，你也可以给它加一行：|1787460|public+int+gcd(int+a,+int+b)+{+return+b==0+?+a+:+gcd(b,+a%25b);+}|1787461|应该注意的是，这两者之间绝对没有区别，因为它们编译成相同的字节码。|1787462|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

As far as I know, there isn't any built-in method for primitives. But something as simple as this should do the trick:

<pre><code>public int gcd(int a, int b) {
 if (b==0) return a;
 return gcd(b,a%b);
}
</code></pre>

You can also one-line it if you're into that sort of thing:

<pre><code>public int gcd(int a, int b) { return b==0 ? a : gcd(b, a%b); }
</code></pre>

It should be noted that there is absolutely no difference between the two as they compile to the same byte code.

blocks|key|2001202|text|或者计算GCD的欧几里德算法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2001203|public+int+egcd(int+a,+int+b)+{
++++if+(a+==+0)
++++++++return+b;

++++while+(b+!=+0)+{
++++++++if+(a+>+b)
++++++++++++a+=+a+-+b;
++++++++else
++++++++++++b+=+b+-+a;
++++}

++++return+a;
}|code-block|syntax|javascript|2001204|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Or the Euclidean algorithm for calculating the GCD...

<pre><code>public int egcd(int a, int b) {
 if (a == 0)
 return b;

 while (b != 0) {
 if (a &gt; b)
 a = a - b;
 else
 b = b - a;
 }

 return a;
}
</code></pre>

blocks|key|2001895|text|除非我有芭乐，否则我是这样定义的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2001896|int+gcd(int+a,+int+b)+{
++return+a+==+0+?+b+:+gcd(b+%25+a,+a);
}|code-block|syntax|javascript|2001897|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Unless I have Guava, I define like this:

<pre><code>int gcd(int a, int b) {
 return a == 0 ? b : gcd(b % a, a);
}
</code></pre>

blocks|key|1787811|text|使用Guava+LongMath.gcd()和IntMath.gcd()|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1787812|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/math/LongMath.html#gcd(long,%2520long)|1|http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/math/IntMath.html#gcd(int,%2520int)^0|8|E|N|D|8|E|0|N|D|1|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]|$9|S|A|T|B|C]]|D|@$9|U|A|V|1|W]|$9|X|A|Y|1|Z]]|E|$]]|$1|F|3|-4|5|6|7|10|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]|N|$5|I|J|K|E|$L|O]]]]

Use Guava <a href="http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/math/LongMath.html#gcd(long,%20long)"><code>LongMath.gcd()</code></a> and <a href="http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/math/IntMath.html#gcd(int,%20int)"><code>IntMath.gcd()</code></a>

blocks|key|1787585|text|雅加达公地数学就是这样。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1787586|ArithmeticUtils.gcd(int+p,+int+q)|offset|length|1787587|entityMap|0|LINK|mutability|MUTABLE|url|https://commons.apache.org/proper/commons-math/javadocs/api-3.5/org/apache/commons/math3/util/ArithmeticUtils.html#gcd(int,%2520int)^0|0|0|X|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|O|8|@]|9|@$D|P|E|Q|1|R]]|A|$]]|$1|F|3|-4|5|6|7|S|8|@]|9|@]|A|$]]]|G|$H|$5|I|J|K|A|$L|M]]]]

Jakarta Commons Math has exactly that.

<a href="https://commons.apache.org/proper/commons-math/javadocs/api-3.5/org/apache/commons/math3/util/ArithmeticUtils.html#gcd(int,%20int)" rel="nofollow noreferrer">ArithmeticUtils.gcd(int p, int q)</a>

blocks|key|1787736|text|您可以使用此Binary+GCD+algorithm实现|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1787737|public+class+BinaryGCD+{

public+static+int+gcd(int+p,+int+q)+{
++++if+(q+==+0)+return+p;
++++if+(p+==+0)+return+q;

++++//+p+and+q+even
++++if+((p+&+1)+==+0+&&+(q+&+1)+==+0)+return+gcd(p+>>+1,+q+>>+1)+<<+1;

++++//+p+is+even,+q+is+odd
++++else+if+((p+&+1)+==+0)+return+gcd(p+>>+1,+q);

++++//+p+is+odd,+q+is+even
++++else+if+((q+&+1)+==+0)+return+gcd(p,+q+>>+1);

++++//+p+and+q+odd,+p+>=+q
++++else+if+(p+>=+q)+return+gcd((p-q)+>>+1,+q);

++++//+p+and+q+odd,+p+<+q
++++else+return+gcd(p,+(q-p)+>>+1);
}

public+static+void+main(String[]+args)+{
++++int+p+=+Integer.parseInt(args[0]);
++++int+q+=+Integer.parseInt(args[1]);
++++System.out.println("gcd("+%2B+p+%2B+",+"+%2B+q+%2B+")+=+"+%2B+gcd(p,+q));
}|code-block|syntax|javascript|1787738|}|1787739|来自http://introcs.cs.princeton.edu/java/23recursion/BinaryGCD.java.html|1787740|entityMap|0|LINK|mutability|MUTABLE|url|https://en.wikipedia.org/wiki/Binary_GCD_algorithm|1|http://introcs.cs.princeton.edu/java/23recursion/BinaryGCD.java.html^0|6|K|0|0|0|0|2|1W|1|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@$A|X|B|Y|1|Z]]|C|$]]|$1|D|3|E|5|F|7|10|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|11|8|@]|9|@]|C|$]]|$1|K|3|L|5|6|7|12|8|@]|9|@$A|13|B|14|1|15]]|C|$]]|$1|M|3|-4|5|6|7|16|8|@]|9|@]|C|$]]]|N|$O|$5|P|Q|R|C|$S|T]]|U|$5|P|Q|R|C|$S|V]]]]

You can use this implementation of <a href="https://en.wikipedia.org/wiki/Binary_GCD_algorithm" rel="noreferrer">Binary GCD algorithm</a>

<pre><code>public class BinaryGCD {

public static int gcd(int p, int q) {
 if (q == 0) return p;
 if (p == 0) return q;

 // p and q even
 if ((p &amp; 1) == 0 &amp;&amp; (q &amp; 1) == 0) return gcd(p &gt;&gt; 1, q &gt;&gt; 1) &lt;&lt; 1;

 // p is even, q is odd
 else if ((p &amp; 1) == 0) return gcd(p &gt;&gt; 1, q);

 // p is odd, q is even
 else if ((q &amp; 1) == 0) return gcd(p, q &gt;&gt; 1);

 // p and q odd, p &gt;= q
 else if (p &gt;= q) return gcd((p-q) &gt;&gt; 1, q);

 // p and q odd, p &lt; q
 else return gcd(p, (q-p) &gt;&gt; 1);
}

public static void main(String[] args) {
 int p = Integer.parseInt(args[0]);
 int q = Integer.parseInt(args[1]);
 System.out.println("gcd(" + p + ", " + q + ") = " + gcd(p, q));
}
</code></pre>

}

From <a href="http://introcs.cs.princeton.edu/java/23recursion/BinaryGCD.java.html" rel="noreferrer">http://introcs.cs.princeton.edu/java/23recursion/BinaryGCD.java.html</a>

blocks|key|2001641|text|如果两个数字都为负数，则此处的某些实现无法正常工作。gcd(-12，-18)是6，而不是-6。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2001642|所以应该返回一个绝对值，例如|2001643|public+static+int+gcd(int+a,+int+b)+{
++++if+(b+==+0)+{
++++++++return+Math.abs(a);
++++}
++++return+gcd(b,+a+%25+b);
}|code-block|syntax|javascript|2001644|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Some implementations here are not working correctly if both numbers are negative. gcd(-12, -18) is 6, not -6.

So an absolute value should be returned, something like

<pre><code>public static int gcd(int a, int b) {
 if (b == 0) {
 return Math.abs(a);
 }
 return gcd(b, a % b);
}
</code></pre>

blocks|key|2001926|text|我们可以使用递归函数来查找gcd|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2001927|public+class+Test
{
+static+int+gcd(int+a,+int+b)
++++{
++++++++//+Everything+divides+0+
++++++++if+(a+==+0+%7C%7C+b+==+0)
+++++++++++return+0;

++++++++//+base+case
++++++++if+(a+==+b)
++++++++++++return+a;

++++++++//+a+is+greater
++++++++if+(a+>+b)
++++++++++++return+gcd(a-b,+b);
++++++++return+gcd(a,+b-a);
++++}

++++//+Driver+method
++++public+static+void+main(String[]+args)+
++++{
++++++++int+a+=+98,+b+=+56;
++++++++System.out.println("GCD+of+"+%2B+a+%2B"+and+"+%2B+b+%2B+"+is+"+%2B+gcd(a,+b));
++++}
}|code-block|syntax|javascript|2001928|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

we can use recursive function for find gcd

<pre><code>public class Test
{
 static int gcd(int a, int b)
 {
 // Everything divides 0 
 if (a == 0 || b == 0)
 return 0;

 // base case
 if (a == b)
 return a;

 // a is greater
 if (a &gt; b)
 return gcd(a-b, b);
 return gcd(a, b-a);
 }

 // Driver method
 public static void main(String[] args) 
 {
 int a = 98, b = 56;
 System.out.println("GCD of " + a +" and " + b + " is " + gcd(a, b));
 }
}
</code></pre>

blocks|key|1788453|text|public+int+gcd(int+num1,+int+num2)+{+
++++int+max+=+Math.abs(num1);
++++int+min+=+Math.abs(num2);

++++while+(max+>+0)+{
++++++++if+(max+<+min)+{
++++++++++++int+x+=+max;
++++++++++++max+=+min;
++++++++++++min+=+x;
++++++++}
++++++++max+%25=+min;
++++}

++++return+min;
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1788454|该方法使用欧几里得算法得到两个整数的“最大公约数”。它接收两个整数并返回它们的gcd。就这么简单！|unstyled|1788455|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>public int gcd(int num1, int num2) { 
 int max = Math.abs(num1);
 int min = Math.abs(num2);

 while (max &gt; 0) {
 if (max &lt; min) {
 int x = max;
 max = min;
 min = x;
 }
 max %= min;
 }

 return min;
}
</code></pre>

This method uses the Euclid’s algorithm to get the "Greatest Common Divisor" of two integers. It receives two integers and returns the gcd of them. just that easy!

blocks|key|2001692|text|如果您使用的是Java1.5或更高版本，那么这是一个迭代的二进制GCD算法，它使用Integer.numberOfTrailingZeros()来减少所需的检查和迭代次数。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2001693|public+class+Utils+{
++++public+static+final+int+gcd(+int+a,+int+b+){
++++++++//+Deal+with+the+degenerate+case+where+values+are+Integer.MIN_VALUE
++++++++//+since+-Integer.MIN_VALUE+=+Integer.MAX_VALUE%2B1
++++++++if+(+a+==+Integer.MIN_VALUE+)
++++++++{
++++++++++++if+(+b+==+Integer.MIN_VALUE+)
++++++++++++++++throw+new+IllegalArgumentException(+"gcd()+is+greater+than+Integer.MAX_VALUE"+);
++++++++++++return+1+<<+Integer.numberOfTrailingZeros(+Math.abs(b)+);
++++++++}
++++++++if+(+b+==+Integer.MIN_VALUE+)
++++++++++++return+1+<<+Integer.numberOfTrailingZeros(+Math.abs(a)+);

++++++++a+=+Math.abs(a);
++++++++b+=+Math.abs(b);
++++++++if+(+a+==+0+)+return+b;
++++++++if+(+b+==+0+)+return+a;
++++++++int+factorsOfTwoInA+=+Integer.numberOfTrailingZeros(a),
++++++++++++factorsOfTwoInB+=+Integer.numberOfTrailingZeros(b),
++++++++++++commonFactorsOfTwo+=+Math.min(factorsOfTwoInA,factorsOfTwoInB);
++++++++a+>>=+factorsOfTwoInA;
++++++++b+>>=+factorsOfTwoInB;
++++++++while(a+!=+b){
++++++++++++if+(+a+>+b+)+{
++++++++++++++++a+=+(a+-+b);
++++++++++++++++a+>>=+Integer.numberOfTrailingZeros(+a+);
++++++++++++}+else+{
++++++++++++++++b+=+(b+-+a);
++++++++++++++++b+>>=+Integer.numberOfTrailingZeros(+b+);
++++++++++++}
++++++++}
++++++++return+a+<<+commonFactorsOfTwo;
++++}
}|code-block|syntax|javascript|2001694|单元测试：|2001695|import+java.math.BigInteger;
import+org.junit.Test;
import+static+org.junit.Assert.*;

public+class+UtilsTest+{
++++@Test
++++public+void+gcdUpToOneThousand(){
++++++++for+(+int+x+=+-1000;+x+<=+1000;+%2B%2Bx+)
++++++++++++for+(+int+y+=+-1000;+y+<=+1000;+%2B%2By+)
++++++++++++{
++++++++++++++++int+gcd+=+Utils.gcd(x,+y);
++++++++++++++++int+expected+=+BigInteger.valueOf(x).gcd(BigInteger.valueOf(y)).intValue();
++++++++++++++++assertEquals(+expected,+gcd+);
++++++++++++}
++++}

++++@Test
++++public+void+gcdMinValue(){
++++++++for+(+int+x+=+0;+x+<+Integer.SIZE-1;+x%2B%2B+){
++++++++++++int+gcd+=+Utils.gcd(Integer.MIN_VALUE,1<<x);
++++++++++++int+expected+=+BigInteger.valueOf(Integer.MIN_VALUE).gcd(BigInteger.valueOf(1<<x)).intValue();
++++++++++++assertEquals(+expected,+gcd+);
++++++++}
++++}
}|2001696|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/7/docs/api/java/lang/Integer.html#numberOfTrailingZeros%2528int%2529^0|15|V|15|V|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|F|3|G|5|H|7|12|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|13|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|14|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]]]

If you are using Java 1.5 or later then this is an iterative binary GCD algorithm which uses <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Integer.html#numberOfTrailingZeros%28int%29" rel="nofollow"><code>Integer.numberOfTrailingZeros()</code></a> to reduce the number of checks and iterations required.

<pre><code>public class Utils {
 public static final int gcd( int a, int b ){
 // Deal with the degenerate case where values are Integer.MIN_VALUE
 // since -Integer.MIN_VALUE = Integer.MAX_VALUE+1
 if ( a == Integer.MIN_VALUE )
 {
 if ( b == Integer.MIN_VALUE )
 throw new IllegalArgumentException( "gcd() is greater than Integer.MAX_VALUE" );
 return 1 &lt;&lt; Integer.numberOfTrailingZeros( Math.abs(b) );
 }
 if ( b == Integer.MIN_VALUE )
 return 1 &lt;&lt; Integer.numberOfTrailingZeros( Math.abs(a) );

 a = Math.abs(a);
 b = Math.abs(b);
 if ( a == 0 ) return b;
 if ( b == 0 ) return a;
 int factorsOfTwoInA = Integer.numberOfTrailingZeros(a),
 factorsOfTwoInB = Integer.numberOfTrailingZeros(b),
 commonFactorsOfTwo = Math.min(factorsOfTwoInA,factorsOfTwoInB);
 a &gt;&gt;= factorsOfTwoInA;
 b &gt;&gt;= factorsOfTwoInB;
 while(a != b){
 if ( a &gt; b ) {
 a = (a - b);
 a &gt;&gt;= Integer.numberOfTrailingZeros( a );
 } else {
 b = (b - a);
 b &gt;&gt;= Integer.numberOfTrailingZeros( b );
 }
 }
 return a &lt;&lt; commonFactorsOfTwo;
 }
}
</code></pre>

Unit test:

<pre><code>import java.math.BigInteger;
import org.junit.Test;
import static org.junit.Assert.*;

public class UtilsTest {
 @Test
 public void gcdUpToOneThousand(){
 for ( int x = -1000; x &lt;= 1000; ++x )
 for ( int y = -1000; y &lt;= 1000; ++y )
 {
 int gcd = Utils.gcd(x, y);
 int expected = BigInteger.valueOf(x).gcd(BigInteger.valueOf(y)).intValue();
 assertEquals( expected, gcd );
 }
 }

 @Test
 public void gcdMinValue(){
 for ( int x = 0; x &lt; Integer.SIZE-1; x++ ){
 int gcd = Utils.gcd(Integer.MIN_VALUE,1&lt;&lt;x);
 int expected = BigInteger.valueOf(Integer.MIN_VALUE).gcd(BigInteger.valueOf(1&lt;&lt;x)).intValue();
 assertEquals( expected, gcd );
 }
 }
}
</code></pre>

blocks|key|1788163|text|/*
import+scanner+and+instantiate+scanner+class;
declare+your+method+with+two+parameters
declare+a+third+variable;
set+condition;
swap+the+parameter+values+if+condition+is+met;
set+second+conditon+based+on+result+of+first+condition;
divide+and+assign+remainder+to+the+third+variable;
swap+the+result;
in+the+main+method,+allow+for+user+input;
Call+the+method;

*/
public+class+gcf+{
++++public+static+void+main+(String[]args){//start+of+main+method
++++++++Scanner+input+=+new+Scanner+(System.in);//allow+for+user+input
++++++++System.out.println("Please+enter+the+first+integer:+");//prompt
++++++++int+a+=+input.nextInt();//initial+user+input
++++++++System.out.println("Please+enter+a+second+interger:+");//prompt
++++++++int+b+=+input.nextInt();//second+user+input


+++++++Divide(a,b);//call+method
++++}
+++public+static+void+Divide(int+a,+int+b)+{//start+of+your+method

++++int+temp;
++++//+making+a+greater+than+b
++++if+(b+>+a)+{
+++++++++temp+=+a;
+++++++++a+=+b;
+++++++++b+=+temp;
++++}

++++while+(b+!=0)+{
++++++++//+gcd+of+b+and+a%25b
++++++++temp+=+a%25b;
++++++++//+always+make+a+greater+than+b
++++++++a+=b;
++++++++b+=temp;

++++}
++++System.out.println(a);//print+to+console
++}
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1788164|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>/*
import scanner and instantiate scanner class;
declare your method with two parameters
declare a third variable;
set condition;
swap the parameter values if condition is met;
set second conditon based on result of first condition;
divide and assign remainder to the third variable;
swap the result;
in the main method, allow for user input;
Call the method;

*/
public class gcf {
 public static void main (String[]args){//start of main method
 Scanner input = new Scanner (System.in);//allow for user input
 System.out.println("Please enter the first integer: ");//prompt
 int a = input.nextInt();//initial user input
 System.out.println("Please enter a second interger: ");//prompt
 int b = input.nextInt();//second user input


 Divide(a,b);//call method
 }
 public static void Divide(int a, int b) {//start of your method

 int temp;
 // making a greater than b
 if (b &gt; a) {
 temp = a;
 a = b;
 b = temp;
 }

 while (b !=0) {
 // gcd of b and a%b
 temp = a%b;
 // always make a greater than b
 a =b;
 b =temp;

 }
 System.out.println(a);//print to console
 }
}
</code></pre>

blocks|key|2002021|text|我使用了我在14岁时创造的这个方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2002022|++++public+static+int+gcd+(int+a,+int+b)+{
++++++++int+s+=+1;
++++++++int+ia+=+Math.abs(a);//<--+turns+to+absolute+value
++++++++int+ib+=+Math.abs(b);
++++++++if+(a+==+b)+{
++++++++++++s+=+a;
++++++++}else+{
++++++++++++while+(ib+!=+ia)+{
++++++++++++++++if+(ib+>+ia)+{
++++++++++++++++++++s+=+ib+-+ia;
++++++++++++++++++++ib+=+s;
++++++++++++++++}else+{+
++++++++++++++++++++s+=+ia+-+ib;
++++++++++++++++++++ia+=+s;
++++++++++++++++}
++++++++++++}
++++++++}
++++++++return+s;
++++}|code-block|syntax|javascript|2002023|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I used this method that I created when I was 14 years old.

<pre><code> public static int gcd (int a, int b) {
 int s = 1;
 int ia = Math.abs(a);//&lt;-- turns to absolute value
 int ib = Math.abs(b);
 if (a == b) {
 s = a;
 }else {
 while (ib != ia) {
 if (ib &gt; ia) {
 s = ib - ia;
 ib = s;
 }else { 
 s = ia - ib;
 ia = s;
 }
 }
 }
 return s;
 }
</code></pre>

blocks|key|1787664|text|这个%25表示两个数字之间的gcd，意思是：-%25或者大数字/小数字的mod+=gcd，我们在java上写成这样的big_number+%25+small_number。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1787665|EX1:对于两个整数|1787666|++public+static+int+gcd(int+x1,int+x2)
++++{
++++++++if(x1>x2)
++++++++{
+++++++++++if(x2!=0)
+++++++++++{
+++++++++++++++if(x1%25x2==0)+++++
+++++++++++++++++++return+x2;
+++++++++++++++++++return+x1%25x2;
+++++++++++++++++++}
+++++++++++return+x1;
+++++++++++}
++++++++++else+if(x1!=0)
++++++++++{
++++++++++++++if(x2%25x1==0)
++++++++++++++++++return+x1;
++++++++++++++++++return+x2%25x1;
++++++++++++++++++}
++++++++return+x2;
++++++++}+|code-block|syntax|javascript|1787667|EX2:三个整数|1787668|public+static+int+gcd(int+x1,int+x2,int+x3)
{

++++int+m,t;
++++if(x1>x2)
++++++++t=x1;
++++t=x2;
++++if(t>x3)
++++++++m=t;
++++m=x3;
++++for(int+i=m;i>=1;i--)
++++{
++++++++if(x1%25i==0+&&+x2%25i==0+&&+x3%25i==0)
++++++++{
++++++++++++return+i;
++++++++}
++++}
++++return+1;
}|1787669|entityMap^0|1I|P|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|V|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|W|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|X|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|Y|8|@]|D|@]|E|$K|L]]|$1|Q|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|R|$]]

The % going to give us the gcd Between two numbers, it means:-
% or mod of big_number/small_number are =gcd,
and we write it on java like this <code>big_number % small_number</code>.

EX1: for two integers

<pre><code> public static int gcd(int x1,int x2)
 {
 if(x1&gt;x2)
 {
 if(x2!=0)
 {
 if(x1%x2==0) 
 return x2;
 return x1%x2;
 }
 return x1;
 }
 else if(x1!=0)
 {
 if(x2%x1==0)
 return x1;
 return x2%x1;
 }
 return x2;
 } 
</code></pre>

EX2: for three integers

<pre><code>public static int gcd(int x1,int x2,int x3)
{

 int m,t;
 if(x1&gt;x2)
 t=x1;
 t=x2;
 if(t&gt;x3)
 m=t;
 m=x3;
 for(int i=m;i&gt;=1;i--)
 {
 if(x1%i==0 &amp;&amp; x2%i==0 &amp;&amp; x3%i==0)
 {
 return i;
 }
 }
 return 1;
}
</code></pre>

I have seen that such a function exists for <code>BigInteger</code>, i.e. <a href="http://docs.oracle.com/javase/7/docs/api/java/math/BigInteger.html#gcd%28java.math.BigInteger%29" rel="noreferrer"><code>BigInteger#gcd</code></a>. Are there other functions in Java which also work for other types (<code>int</code>, <code>long</code> or <code>Integer</code>)? It seems this would make sense as <code>java.lang.Math.gcd</code> (with all kinds of overloads) but it is not there. Is it somewhere else?

<hr>

(Don't confuse this question with "how do I implement this myself", please!)

Java: get greatest common divisor

单元测试

Java

我已经看到BigInteger存在这样一个函数，即。Java中是否有其他函数也适用于其他类型(int、long或Integer)？这看起来像java.lang.Math.gcd一样有意义(有各种重载)，但它不在那里。是在别的地方吗？(请不要将这个问题与“我如何自己实现这个”混淆起来！)

问Java:获取最大公约数
EN

回答 14

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问Java:获取最大公约数EN

回答 14

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问Java:获取最大公约数
EN