Expression Add Operators
Advanced Backtracking DSA practice problem on Onlearn.
Difficulty: hard.
Topics: What are the possible approaches to solving the 'Expression Add Operators' problem and what are their underlying concepts and complexities?, Backtracking, Recursion, String Manipulation, Data Types, string manipulation, backtracking, combinatorics, expression evaluation, recursion, Expression Evaluation, Subset & Permutation Problems.
Given a string num that contains only digits and an integer target, return all possible expressions that you can insert the binary operators +, , and between the digits of num such that the expression evaluates to the target value. Input Specification The input consists of two parts: A string num consisting of digits '0' '9'. An integer target. Output Specification Return a list of strings, where each string is a valid expression that evaluates to target. Constraints 1 <= num.length <= 10 num consists of only digits. 2^31 <= target <= 2^31 1 Sample Test Cases Input: num = "123" target = 6 Output: ["1+2+3", "1 2 3"]