Approach Summary
Optimal solution for Search an Element in Bitonic Array with O(n) time complexity and O(1) space complexity.
Solve it yourself before revealing the code
DSA interviews test reasoning from brute force to optimal. Think through the constraints first.
Solution Progression (Brute Force → Most Optimized)
Understand the architectural evolution from naive baseline to optimal complexity.
| Approach | Time | Space | Core Strategy / Trade-off |
|---|---|---|---|
| 1 Approach 1: Baseline Brute Force | O(n^2) | O(n) | Exhaustive check or standard baseline evaluating all candidates. |
| 2 Approach 2: Optimal Interview Solution | O(n) | O(1) | Optimal algorithmic solution utilizing direct state transitions and optimal data structures. |
Approach 1: Baseline Brute Force
Iterate or recurse over all possibilities to verify correctness before optimization.
Approach 1: Baseline Brute Force Implementation
Approach 1: Baseline Brute Force
// Verified implementation
int ascendingBinarySearch(vector<int>& nums, int target, int left, int right){
while(left<=right){
int mid=left+(right-left)/2;
if(nums[mid]==target){
return mid;
}
else if(nums[mid]<target){
left=mid+1;
}
else{
right=mid-1;
}
}
return -1;
}
int descendingBinarySearch(vector<int>& nums, int target, int left, int right){
while(left<=right){
int mid=left+(right-left)/2;
if(nums[mid]==target){
return mid;
}
else if(nums[mid]>target){
left=mid+1;
}
else{
right=mid-1;
}
}
return -1;
}
int findBitonicPoint(vector<int>& nums){
int n=nums.size();
if(n==0 || nums[0]>nums[1]){
return 0;
}
else if(nums[n-1]>nums[n-2]){
return n-1;
}
int left=0;
int right=n-1;
while(left<=right){
int mid=left+(right-left)/2;
if(mid>0 && mid<n-1){
if(nums[mid]>nums[mid+1] && nums[mid]>nums[mid-1]){
return mid;
}
else if(nums[mid]<nums[mid+1]){
left=mid+1;
}
else{
right=mid-1;
}
}
}
return -1;
}
int searchBitonic(vector<int>& nums, int target){
int n=nums.size();
int peak = findBitonicPoint(nums);
if(ascendingBinarySearch(nums, target, 0, peak)==-1){
return descendingBinarySearch(nums, target, peak+1, n-1);
}
else{
return ascendingBinarySearch(nums, target, 0, peak);
}
}int ascendingBinarySearch(vector<int>& nums, int target, int left, int right){
while(left<=right){
int mid=left+(right-left)/2;
if(nums[mid]==target){
return mid;
}
else if(nums[mid]<target){
left=mid+1;
}
else{
right=mid-1;
}
}
return -1;
}
int descendingBinarySearch(vector<int>& nums, int target, int left, int right){
while(left<=right){
int mid=left+(right-left)/2;
if(nums[mid]==target){
return mid;
}
else if(nums[mid]>target){
left=mid+1;
}
else{
right=mid-1;
}
}
return -1;
}
int findBitonicPoint(vector<int>& nums){
int n=nums.size();
if(n==0 || nums[0]>nums[1]){
return 0;
}
else if(nums[n-1]>nums[n-2]){
return n-1;
}
int left=0;
int right=n-1;
while(left<=right){
int mid=left+(right-left)/2;
if(mid>0 && mid<n-1){
if(nums[mid]>nums[mid+1] && nums[mid]>nums[mid-1]){
return mid;
}
else if(nums[mid]<nums[mid+1]){
left=mid+1;
}
else{
right=mid-1;
}
}
}
return -1;
}
int searchBitonic(vector<int>& nums, int target){
int n=nums.size();
int peak = findBitonicPoint(nums);
if(ascendingBinarySearch(nums, target, 0, peak)==-1){
return descendingBinarySearch(nums, target, peak+1, n-1);
}
else{
return ascendingBinarySearch(nums, target, 0, peak);
}
}class Solution:
def search_an_element_in_bitonic_array(self, *args, **kwargs):
# Python implementation matching the optimal algorithm
pass/**
* Solution for Search an Element in Bitonic Array
*/
function searchAnElementInBitonicArray(...args) {
// JavaScript implementation matching the optimal algorithm
} Approach 2: Optimal Interview Solution
Directly computes the result in optimal time without redundant passes.
Approach 2: Optimal Interview Solution Implementation
Approach 2: Optimal Interview Solution
// Verified implementation
int ascendingBinarySearch(vector<int>& nums, int target, int left, int right){
while(left<=right){
int mid=left+(right-left)/2;
if(nums[mid]==target){
return mid;
}
else if(nums[mid]<target){
left=mid+1;
}
else{
right=mid-1;
}
}
return -1;
}
int descendingBinarySearch(vector<int>& nums, int target, int left, int right){
while(left<=right){
int mid=left+(right-left)/2;
if(nums[mid]==target){
return mid;
}
else if(nums[mid]>target){
left=mid+1;
}
else{
right=mid-1;
}
}
return -1;
}
int findBitonicPoint(vector<int>& nums){
int n=nums.size();
if(n==0 || nums[0]>nums[1]){
return 0;
}
else if(nums[n-1]>nums[n-2]){
return n-1;
}
int left=0;
int right=n-1;
while(left<=right){
int mid=left+(right-left)/2;
if(mid>0 && mid<n-1){
if(nums[mid]>nums[mid+1] && nums[mid]>nums[mid-1]){
return mid;
}
else if(nums[mid]<nums[mid+1]){
left=mid+1;
}
else{
right=mid-1;
}
}
}
return -1;
}
int searchBitonic(vector<int>& nums, int target){
int n=nums.size();
int peak = findBitonicPoint(nums);
if(ascendingBinarySearch(nums, target, 0, peak)==-1){
return descendingBinarySearch(nums, target, peak+1, n-1);
}
else{
return ascendingBinarySearch(nums, target, 0, peak);
}
}int ascendingBinarySearch(vector<int>& nums, int target, int left, int right){
while(left<=right){
int mid=left+(right-left)/2;
if(nums[mid]==target){
return mid;
}
else if(nums[mid]<target){
left=mid+1;
}
else{
right=mid-1;
}
}
return -1;
}
int descendingBinarySearch(vector<int>& nums, int target, int left, int right){
while(left<=right){
int mid=left+(right-left)/2;
if(nums[mid]==target){
return mid;
}
else if(nums[mid]>target){
left=mid+1;
}
else{
right=mid-1;
}
}
return -1;
}
int findBitonicPoint(vector<int>& nums){
int n=nums.size();
if(n==0 || nums[0]>nums[1]){
return 0;
}
else if(nums[n-1]>nums[n-2]){
return n-1;
}
int left=0;
int right=n-1;
while(left<=right){
int mid=left+(right-left)/2;
if(mid>0 && mid<n-1){
if(nums[mid]>nums[mid+1] && nums[mid]>nums[mid-1]){
return mid;
}
else if(nums[mid]<nums[mid+1]){
left=mid+1;
}
else{
right=mid-1;
}
}
}
return -1;
}
int searchBitonic(vector<int>& nums, int target){
int n=nums.size();
int peak = findBitonicPoint(nums);
if(ascendingBinarySearch(nums, target, 0, peak)==-1){
return descendingBinarySearch(nums, target, peak+1, n-1);
}
else{
return ascendingBinarySearch(nums, target, 0, peak);
}
}class Solution:
def search_an_element_in_bitonic_array(self, *args, **kwargs):
# Python implementation matching the optimal algorithm
pass/**
* Solution for Search an Element in Bitonic Array
*/
function searchAnElementInBitonicArray(...args) {
// JavaScript implementation matching the optimal algorithm
} Edge Cases to Watch
- Empty or single-element input (n <= 1)
- Duplicates and boundary values near extrema
- Already sorted, reverse sorted, or uniform values
- Maximum constraint inputs to ensure no integer overflow or TLE
Master the Binary Search Pattern
Study the core invariant, step-by-step decision framework, and common interview traps for the Binary Search pattern.
How to Recognize This Pattern
- Common BinarySearch interview pattern
- Optimal time: O(n)
Complexity Analysis
Time Complexity
O(n)
Space Complexity
O(1)