Leetcode•Jun 09, 2025

Different Ways to Add Parentheses

Hazrat Ali

Leetcode

Given a string expression of numbers and operators, return all possible results from computing all the different possible ways to group numbers and operators. You may return the answer in any order.

The test cases are generated such that the output values fit in a 32-bit integer and the number of different results does not exceed 104.

 

Example 1:

Input: expression = "2-1-1"
Output: [0,2]
Explanation:
((2-1)-1) = 0 
(2-(1-1)) = 2

Example 2:

Input: expression = "2*3-4*5"
Output: [-34,-14,-10,-10,10]
Explanation:
(2*(3-(4*5))) = -34 
((2*3)-(4*5)) = -14 
((2*(3-4))*5) = -10 
(2*((3-4)*5)) = -10 
(((2*3)-4)*5) = 10


Solution

/**
 * @param {string} input
 * @return {number[]}
 */
const diffWaysToCompute = input => {
  const result = [];

  for (let i = 1; i < input.length; i++) {
    const c = input[i];

    if (c === '+' || c === '-' || c === '*') {
      const s1 = input.substring(0, i);
      const s2 = input.substring(i + 1);

      const l1 = diffWaysToCompute(s1);
      const l2 = diffWaysToCompute(s2);

      for (let n1 of l1) {
        for (let n2 of l2) {
          switch (c) {
            case '+':
              result.push(n1 + n2);
              break;
            case '-':
              result.push(n1 - n2);
              break;
            case '*':
              result.push(n1 * n2);
              break;
          }
        }
      }
    }
  }

  if (result.length === 0) {
    result.push(parseInt(input));
  }

  return result;
};





Comments

Different Ways to Add Parentheses