标签：output lis ring different length sub str i++ rom
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]
分析：
加了括号以后，每一个operator在某种情况下都会被最后执行。
public List<Integer> diffWaysToCompute(String input) { List<Integer> list = new ArrayList<Integer>(); for (int i = 0; i < input.length(); i++) { if (input.charAt(i) == ‘+‘ || input.charAt(i) == ‘-‘ || input.charAt(i) == ‘*‘) { List<Integer> left = diffWaysToCompute(input.substring(0, i)); List<Integer> right = diffWaysToCompute(input.substring(i + 1)); for (int l : left) { for (int r : right) { if (input.charAt(i) == ‘+‘) { list.add(l + r); } else if (input.charAt(i) == ‘-‘) { list.add(l - r); } else if (input.charAt(i) == ‘*‘) { list.add(l * r); } } } } } if (list.size() == 0) { list.add(Integer.parseInt(input)); } return list; }
Different Ways to Add Parentheses
标签：output lis ring different length sub str i++ rom
原文地址：http://www.cnblogs.com/beiyeqingteng/p/6193577.html
