LeetCode 241: Different Ways to Add Parentheses Solution
Master LeetCode problem 241 (Different Ways to Add Parentheses), a medium challenge, with our optimized solutions in Java, C++, and Python. Explore detailed explanations, test your code in our interactive editor, and prepare for coding interviews.
241. Different Ways to Add Parentheses
Problem Explanation
Explanation
To solve this problem, we can use a divide and conquer approach combined with recursion. We will iterate through the expression and whenever we encounter an operator, we will split the expression into two parts around that operator. We will then recursively calculate the results for both parts and combine them in all possible ways according to the operator encountered.
This recursive approach will generate all possible ways to group numbers and operators. We will keep track of the intermediate results for each combination of grouping. Finally, we return all possible results.
Time Complexity: The time complexity of this approach is exponential as we are exploring all possible grouping combinations. It can be represented as O(4^n) where n is the number of operators in the expression.
Space Complexity: The space complexity is also exponential due to the recursive nature of the algorithm and the need to store intermediate results. It can be represented as O(4^n).
Solution Code
class Solution {
public List<Integer> diffWaysToCompute(String expression) {
List<Integer> result = new ArrayList<>();
for (int i = 0; i < expression.length(); i++) {
char c = expression.charAt(i);
if (c == '+' || c == '-' || c == '*') {
List<Integer> left = diffWaysToCompute(expression.substring(0, i));
List<Integer> right = diffWaysToCompute(expression.substring(i + 1));
for (int num1 : left) {
for (int num2 : right) {
if (c == '+') {
result.add(num1 + num2);
} else if (c == '-') {
result.add(num1 - num2);
} else if (c == '*') {
result.add(num1 * num2);
}
}
}
}
}
if (result.isEmpty()) {
result.add(Integer.parseInt(expression));
}
return result;
}
}Try It Yourself
Loading code editor...
Related LeetCode Problems
Frequently Asked Questions
How to solve LeetCode 241 (Different Ways to Add Parentheses)?
This page provides optimized solutions for LeetCode problem 241 (Different Ways to Add Parentheses) in Java, C++, and Python, along with a detailed explanation and an interactive code editor to test your code.
What is the time complexity of LeetCode 241 (Different Ways to Add Parentheses)?
The time complexity for LeetCode 241 (Different Ways to Add Parentheses) varies by solution. Check the detailed explanation section for specific complexities in Java, C++, and Python implementations.
Can I run code for LeetCode 241 on DevExCode?
Yes, DevExCode provides an interactive code editor where you can write, test, and run your code for LeetCode 241 in Java, C++, or Python.