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 ' '
public class StringIterator {
int i;
String[] arr;
int[] counts; public StringIterator(String str) {
arr = str.split("\\d+");
counts = Arrays.stream(str.substring().split("[a-zA-Z]+")).mapToInt(Integer::parseInt).toArray();
} public char next() {
if (!hasNext()) {
return ' ';
}
char ch = arr[i].charAt();
counts[i]--; if (counts[i] == ) {
++i;
}
return ch;
} public boolean hasNext() {
if (i == arr.length) {
return false;
}
return true;
}
}