Lintcode BS Search Insert Position
19 Dec 2015###Task1 Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.
You may assume NO duplicates in the array.
Have you met this question in a real interview? Yes Example
[1,3,5,6], 5 → 2
[1,3,5,6], 2 → 1
[1,3,5,6], 7 → 4
[1,3,5,6], 0 → 0
Challenge O(log(n)) time
###java
public class Solution {
/**
* param A : an integer sorted array
* param target : an integer to be inserted
* return : an integer
*/
public int searchInsert(int[] A, int target) {
// write your code here
// find the first pos larger or equal to target
if (A == null || A.length == 0) {
return 0;
}
int start = 0;
int end = A.length - 1;
int mid;
while (start + 1 < end) {
mid = start + (end - start) / 2;
if (A[mid] >= target) {
end = mid;
} else {
start = mid;
}
}
if (A[start] >= target) {
return start;
} else if (A[end] >= target) {
return end;
}
return A.length;
}
}
###Points
- Find the first element >= target or the last element that <= target.