Solution.java

/**
 * // This is the interface that allows for creating nested lists.
 * // You should not implement it, or speculate about its implementation
 * public interface NestedInteger {
 *     // Constructor initializes an empty nested list.
 *     public NestedInteger();
 *
 *     // Constructor initializes a single integer.
 *     public NestedInteger(int value);
 *
 *     // @return true if this NestedInteger holds a single integer, rather than a nested list.
 *     public boolean isInteger();
 *
 *     // @return the single integer that this NestedInteger holds, if it holds a single integer
 *     // Return null if this NestedInteger holds a nested list
 *     public Integer getInteger();
 *
 *     // Set this NestedInteger to hold a single integer.
 *     public void setInteger(int value);
 *
 *     // Set this NestedInteger to hold a nested list and adds a nested integer to it.
 *     public void add(NestedInteger ni);
 *
 *     // @return the nested list that this NestedInteger holds, if it holds a nested list
 *     // Return null if this NestedInteger holds a single integer
 *     public List<NestedInteger> getList();
 * }
 */
public class Solution {
    public NestedInteger deserialize(String s) {
        if (s.contains("[")) {
            NestedInteger ans=new NestedInteger();
            if (s.length()>2) {
                int begin=1;
                char[] cs=s.toCharArray();
                int count=0;
                for (int i = 1; i < s.length()-1; i++) {
                    if (cs[i]==','&&count==0) {
                        ans.add(deserialize(s.substring(begin,i)));
                        begin=i+1;
                    }
                    if (cs[i]=='['||cs[i]==']') {
                        count+=(92-cs[i]);
                    }
                }
                ans.add(deserialize(s.substring(begin,s.length()-1)));
            }
            return ans;
        }
        return new NestedInteger(Integer.valueOf(s));
    }
}