http://blog.csdn.net/lpjishu/article/details/51842185?ref=myread#comments

题目描述：

输入2个数字，最后输出2个数字的最大公约数

思路分析：

• 首先这个题目是有技巧的，利用下面代码中的求余 
  -注意检查a，b是《=0的情况

注意：

• 首先注意输入法的一致，不然编译报错
• 注意在mian中调用的工具方法，声明位静态方法

代码：

<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: "Source Code Pro", monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">import java.util.Scanner;

<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">class</span> Main {
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">main</span>(String[] args) {
        Scanner scan = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Scanner(System.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">in</span>);
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">while</span>(scan.hasNext()){
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> a1 = scan.nextInt();
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> a2 = scan.nextInt();
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span>(a1 <= <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>|| a2 <= <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>){
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span>;
        }
        System.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">out</span>.println(getMax(a1,a2));
    }       
    }
   <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//求两个数字的最大公约数</span>
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> <span class="hljs-title" style="box-sizing: border-box;">getMax</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> a,<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> b){
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> temp = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">while</span>(a != <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>){
            temp = a;
            a = b % a;
            b = temp;
        }
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> b;
    }
}</code>