[LeetCode] Different Ways to Add Parentheses

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## [LeetCode] Different Ways to Add Parentheses

Given a string of numbers and operators, return all possible results from computing all the different possible ways to group numbers and operators. The valid operators are `+`, `-` and `*`.

Example 1

Input: `"2-1-1"`.

((2-1)-1) = 0
(2-(1-1)) = 2

Output: `[0, 2]`

Example 2

Input: `"2*3-4*5"`

(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

Output: `[-34, -14, -10, -10, 10]`

# 实现代码

Java：

``````// Runtime: 6 ms
public class Solution {
public List<Integer> diffWaysToCompute(String input) {
List<Integer> res = new ArrayList<Integer>();
for (int i = 0; i < input.length(); i++) {
char ch = input.charAt(i);
if (ch == '+' || ch == '-' || ch == '*') {
List<Integer> left = diffWaysToCompute(input.substring(0, i));
List<Integer> right = diffWaysToCompute(input.substring(i + 1));
for (int n : left) {
for (int m : right) {
switch (ch) {
case '+':
break;
case '-':
break;

case '*':
break;
}
}
}
}
}

if (res.size() == 0) {