帮我用JAVA写一个二分查找
时间: 2023-03-29 16:03:06 浏览: 46
好的,这是 Java 代码实现的二分查找:
```
public class BinarySearch {
public static int binarySearch(int[] arr, int target) {
int left = 0;
int right = arr.length - 1;
while (left <= right) {
int mid = (left + right) / 2;
if (arr[mid] == target) {
return mid;
} else if (arr[mid] < target) {
left = mid + 1;
} else {
right = mid - 1;
}
}
return -1;
}
public static void main(String[] args) {
int[] arr = {1, 2, 3, 4, 5};
int target = 4;
int result = binarySearch(arr, target);
System.out.println("The target is located at index: " + result);
}
}
```
这个代码实现了一个简单的二分查找,如果找到了目标值,就返回目标值所在的索引;如果没有找到目标值,就返回 -1。