# 几种查找算法Java实现

Java 算法 C/C++ 11684 次浏览
```    /**
* 类名：SearchTest.java
* 说明: 几种查找方法
*/
public class SearchTest {

/**
* 函数名称：binarySearch
* 说明：二分查找 时间复杂度O(logN)
*/
//驱动例程
public static <AnyType extends Comparable<? super AnyType>> int  binary(AnyType[] a,AnyType x){
return binary(a,0,a.length-1,x);
}
//递归
/*    public static <AnyType extends Comparable<? super AnyType>> int binary(AnyType[] a,int low,int high,AnyType x){
if(low > high)
return -1;
int mid = (low + high)/2;
if(a[mid].compareTo(x) > 0 )
return binary(a,low,mid - 1,x);
else if(a[mid].compareTo(x) < 0 )
return binary(a,mid+1,high,x);
else return mid;

}*/
//非递归
public static <AnyType extends Comparable<? super AnyType>> int binary(AnyType[] a,int low,int high,AnyType x){

while(low <= high){
int mid = (low + high)/2;
if(a[mid].compareTo(x) > 0)
high = mid -1;
else if(a[mid].compareTo(x) < 0)
low = mid + 1;
else
return mid;
}
return -1;
}
/**
* 函数名称：main
* 说明：测试
*/
public static void main(String[] args) {
// TODO 自动生成的方法存根
Integer[] a = new Integer[]{1,2,3,4,5,6};
int x = 3;
System.out.println(binary(a,x));
}

}  ```