Given a nested list of integers represented as a string, implement a parser to deserialize it.
Each element is either an integer, or a list -- whose elements may also be integers or other lists.
Note: You may assume that the string is well-formed:
String is non-empty.
String does not contain white spaces.
String contains only digits 0-9, [, - ,, ].
Example 1:
Given s = "324",
You should return a NestedInteger object which contains a single integer 324.
Example 2:
Given s = "[123,[456,[789]]]",
Return a NestedInteger object containing a nested list with 2 elements:
1. An integer containing value 123.
2. A nested list containing two elements:
i. An integer containing value 456.
ii. A nested list with one element:
a. An integer containing value 789.
详见：https://leetcode.com/problems/mini-parser/description/
C++：
/**
* // This is the interface that allows for creating nested lists.
* // You should not implement it, or speculate about its implementation
* class NestedInteger {
* public:
* // Constructor initializes an empty nested list.
* NestedInteger();
*
* // Constructor initializes a single integer.
* NestedInteger(int value);
*
* // Return true if this NestedInteger holds a single integer, rather than a nested list.
* bool isInteger() const;
*
* // Return the single integer that this NestedInteger holds, if it holds a single integer
* // The result is undefined if this NestedInteger holds a nested list
* int getInteger() const;
*
* // Set this NestedInteger to hold a single integer.
* void setInteger(int value);
*
* // Set this NestedInteger to hold a nested list and adds a nested integer to it.
* void add(const NestedInteger &ni);
*
* // Return the nested list that this NestedInteger holds, if it holds a nested list
* // The result is undefined if this NestedInteger holds a single integer
* const vector<NestedInteger> &getList() const;
* };
*/
class Solution {
public:
NestedInteger deserialize(string s) {
if(s.empty())
{
return NestedInteger();
}
if(s[0]!='[')
{
return NestedInteger(stoi(s));
}
if(s.size()<=2)
{
return NestedInteger();
}
NestedInteger res;
int cnt=0;
int start=1;
for(int i=1;i<s.size();++i)
{
if(cnt==0&&s[i]==','||i==s.size()-1)
{
res.add(deserialize(s.substr(start,i-start)));
start=i+1;
}
else if(s[i]=='[')
{
++cnt;
}
else if(s[i]==']')
{
--cnt;
}
}
return res;
}
};
参考：https://www.cnblogs.com/grandyang/p/5771434.html