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35.Search-Insert-Position
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.
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
Appraoch 1: Find the first position
public class Solution {
public int searchInsert(int[] A, int target) {
if (A == null | A.length == 0) return 0;
int start = 0;
int end = A.length - 1;
while (start + 1 < end) {
int mid = start + (end - start) / 2;
if (A[mind] == target) {
return mid;
} else if (A[mid] < target) {
start = mid;
} else {
end = mid;
}
}
if (A[start] >= target) {
return start;
} else if (A[end] >= target) {
return end;
} else {
return end + 1;
}
/// approach 2:
if (target < A[0]) return 0;
if (A[end] == target) return end;
if (A[start] == target) return start;
if (A[end] < target) return end + 1;
return start + 1;
}
}