Given an array of integers sorted in ascending order, find the starting and ending position of a given target value.
Your algorithm's runtime complexity must be in the order of O(log n).
If the target is not found in the array, return [-1, -1]
.
For example,
Given [5, 7, 7, 8, 8, 10]
and target value 8,
return [3, 4]
.
给定按升序排序的整数数组,找到给定目标值的开始和结束位置。算法的时间复杂度为O(log n)。如果在数组中找不到目标,则返回[-1,-1]。
代码如下:
public class SearchforARange {
public static void main(String[] args) {
int[] nums = new int[]{5, 7, 7, 8, 8, 10};
int[] searchRange = searchRange(nums, 8);
for (int i = 0; i < 2; i++) {
System.out.print(searchRange[i]+",");
}
}
public static int[] searchRange(int[] nums, int target) {
int[] result = new int[]{-1,-1};
if(nums.length < 0) {
return result;
}
int start=0;
int end = nums.length-1;
for(;start<nums.length;start++) {
if(nums[start] == target) {
result[0]=start;
break;
}
}
for(;end>=start;end--){
if(nums[end] == target) {
result[1]=end;
break;
}
}
return result;
}
}