public class Solution {
public IList<int> DiffWaysToCompute(string input) {
List<int> ret = new List<int>();
for (int i = ; i < input.Length; i++)
{
if (input[i] == '-' ||
input[i] == '*' ||
input[i] == '+')
{
string part1 = input.Substring(, i);
string part2 = input.Substring(i + );
var part1Ret = DiffWaysToCompute(part1);
var part2Ret = DiffWaysToCompute(part2);
foreach (var p1 in part1Ret)
{
foreach (var p2 in part2Ret)
{
int c = ;
switch (input[i])
{
case '+': c = p1 + p2;
break;
case '-': c = p1 - p2;
break;
case '*': c = p1 * p2;
break;
}
ret.Add(c);
}
}
}
}
if (ret.Count == )
{
ret.Add(int.Parse(input));
}
return ret;
}
}
https://leetcode.com/problems/different-ways-to-add-parentheses/
补充一个python的
class Solution:
def diffWaysToCompute(self, input: str) -> 'List[int]':
re = list()
n = len(input)
for i in range(n):
c = input[i]
if c =='+' or c == '-' or c == '*':
left = input[:i]
right = input[i+:]
for l in self.diffWaysToCompute(left):
for r in self.diffWaysToCompute(right):
if c == '+':
re.append(l + r)
elif c == '-':
re.append(l - r)
elif c == '*':
re.append(l * r)
if len(re) == :
re.append(int(input))
return re
实现：
