-
Notifications
You must be signed in to change notification settings - Fork 2
/
SearchInInfiniteArray.java
69 lines (59 loc) · 1.95 KB
/
SearchInInfiniteArray.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
package Leetcode;
/**
* @author kalpak
*
* Given an integer array sorted in ascending order, write a function to search target in nums.
* If target exists, then return its index, otherwise return -1. However, the array size is unknown to you.
* You may only access the array using an ArrayReader interface, where ArrayReader.get(k) returns the element of the array at index k (0-indexed).
*
* You may assume all integers in the array are less than 10000, and if you access the array out of bounds, ArrayReader.get will return 2147483647.
*
* Example 1:
* Input: array = [-1,0,3,5,9,12], target = 9
* Output: 4
* Explanation: 9 exists in nums and its index is 4
*
* Example 2:
* Input: array = [-1,0,3,5,9,12], target = 2
* Output: -1
* Explanation: 2 does not exist in nums so return -1
*
* Constraints:
*
* You may assume that all elements in the array are unique.
* The value of each element in the array will be in the range [-9999, 9999].
* The length of the array will be in the range [1, 10^4].
*/
class ArrayReader {
int[] arr;
ArrayReader(int[] arr) {
this.arr = arr;
}
public int get(int index) {
if (index >= arr.length)
return Integer.MAX_VALUE;
return arr[index];
}
}
public class SearchInInfiniteArray {
public static int search(ArrayReader reader, int target) {
int left = 0;
int right = 1;
while(reader.get(right) < target)
right *= 2;
while(left <= right) {
int mid = left + (right - left)/2;
if(target == reader.get(mid))
return mid;
if(reader.get(mid) < target)
left = mid + 1;
else
right = mid - 1;
}
return -1;
}
public static void main(String[] args) {
ArrayReader reader = new ArrayReader(new int[] { 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30 });
System.out.println(search(reader, 14));
}
}