Design and implement a data structure for a compressed string iterator. It should support the following operations: next and hasNext.
The given compressed string will be in the form of each letter followed by a positive integer representing the number of this letter existing in the original uncompressed string.
next() - if the original string still has uncompressed characters, return the next letter; Otherwise return a white space.hasNext() - Judge whether there is any letter needs to be uncompressed.
Note:
Please remember to RESET your class variables declared in StringIterator, as static/class variables are persisted across multiple test cases. Please see here for more details.
Example:
StringIterator iterator = new StringIterator("L1e2t1C1o1d1e1");
iterator.next(); // return 'L'
iterator.next(); // return 'e'
iterator.next(); // return 'e'
iterator.next(); // return 't'
iterator.next(); // return 'C'
iterator.next(); // return 'o'
iterator.next(); // return 'd'
iterator.hasNext(); // return true
iterator.next(); // return 'e'
iterator.hasNext(); // return false
iterator.next(); // return ' '
思路：
需要注意的是，数字可能是大于10的也就是说不一定是一位数。。。
参考了大神的代码。。
class StringIterator {
string a;
size_t i = , c = ;
char ch;
public:
StringIterator(string a) {
this->a = a;
}
char next() {
if (c)
return c--, ch;
if (i >= a.size())
return ' ';
ch = a[i++];
while (i < a.size() && isdigit(a[i]))
c = c*+a[i++]-'';
c--;
return ch;
}
bool hasNext() {
return c || i < a.size();
}
};
参考：