Approach Summary
Backtracking: try every prefix from the current position. If it's a palindrome, recurse on the remainder. Collect complete partitions.
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(2^n) | O(n^2) | Exhaustive check or standard baseline evaluating all candidates. |
| 2 Approach 2: Optimal Interview Solution | O(n*2^n) | O(n*2^n) | 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
class Solution {
public boolean isPalindrome(String s, int start, int end){
while(start < end){
if(s.charAt(start) != s.charAt(end)){
return false;
}
start++;
end--;
}
return true;
}
public void solvePartition(String s, int start, List<String> current, List<List<String>> result){
if(start == s.length()){
result.add(new ArrayList<>(current));
return;
}
for(int end=start; end<s.length(); end++){
if(isPalindrome(s, start, end)){
current.add(s.substring(start, end+1));
solvePartition(s, end+1, current, result);
current.remove(current.size()-1);
}
}
}
public List<List<String>> partition(String s) {
List<List<String>> result = new ArrayList<>();
List<String> current = new ArrayList<>();
solvePartition(s, 0, current, result);
return result;
}
}class Solution {
public:
bool isPalindrome(string &s, int start, int end){
while(start < end){
if(s[start] != s[end]){
return false;
}
start++;
end--;
}
return true;
}
void solvePartition(string &s, int start, vector<string> ¤t, vector<vector<string>> &result){
if(start == s.size()){
result.push_back(current);
return;
}
for(int end=start; end<s.size(); end++){
if(isPalindrome(s, start, end)){
current.push_back(s.substr(start, end-start+1));
solvePartition(s, end+1, current, result);
current.pop_back();
}
}
}
vector<vector<string>> partition(string s) {
vector<vector<string>> result;
vector<string> current;
solvePartition(s, 0, current, result);
return result;
}
};class Solution:
def palindrome_partitioning(self, *args, **kwargs):
# Python implementation matching the optimal algorithm
pass/**
* Solution for Palindrome Partitioning
*/
function palindromePartitioning(...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
class Solution {
public boolean isPalindrome(String s, int start, int end){
while(start < end){
if(s.charAt(start) != s.charAt(end)){
return false;
}
start++;
end--;
}
return true;
}
public void solvePartition(String s, int start, List<String> current, List<List<String>> result){
if(start == s.length()){
result.add(new ArrayList<>(current));
return;
}
for(int end=start; end<s.length(); end++){
if(isPalindrome(s, start, end)){
current.add(s.substring(start, end+1));
solvePartition(s, end+1, current, result);
current.remove(current.size()-1);
}
}
}
public List<List<String>> partition(String s) {
List<List<String>> result = new ArrayList<>();
List<String> current = new ArrayList<>();
solvePartition(s, 0, current, result);
return result;
}
}class Solution {
public:
bool isPalindrome(string &s, int start, int end){
while(start < end){
if(s[start] != s[end]){
return false;
}
start++;
end--;
}
return true;
}
void solvePartition(string &s, int start, vector<string> ¤t, vector<vector<string>> &result){
if(start == s.size()){
result.push_back(current);
return;
}
for(int end=start; end<s.size(); end++){
if(isPalindrome(s, start, end)){
current.push_back(s.substr(start, end-start+1));
solvePartition(s, end+1, current, result);
current.pop_back();
}
}
}
vector<vector<string>> partition(string s) {
vector<vector<string>> result;
vector<string> current;
solvePartition(s, 0, current, result);
return result;
}
};class Solution:
def palindrome_partitioning(self, *args, **kwargs):
# Python implementation matching the optimal algorithm
pass/**
* Solution for Palindrome Partitioning
*/
function palindromePartitioning(...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 Backtracking Pattern
Study the core invariant, step-by-step decision framework, and common interview traps for the Backtracking pattern.
How to Recognize This Pattern
- "All ways to partition string into palindromes"
- Backtracking + palindrome check precomputed with DP
Complexity Analysis
Time Complexity
O(n × 2ⁿ)
Space Complexity
O(n)