Count and Say
The count-and-say sequence is the sequence of integers beginning as follows:
1, 11, 21, 1211, 111221, ...
1
is read off as "one 1"
or 11
.
11
is read off as "two 1s"
or 21
.
21
is read off as "one 2, then one 1"
or 1211
.
Given an integer n, generate the nth sequence.
Note: The sequence of integers will be represented as a string.
Solution:
public class Solution {
public String countAndSay(int n) {
String t, s = "1";
while (n-- > 1) {
int c = 0;
t = "";
for (int i = 0; i <= s.length(); i++) {
if (i == s.length() || (i > 0 && s.charAt(i) != s.charAt(i - 1))) {
t += String.valueOf(c) + s.charAt(i - 1); c = 0; // say
}
c++; // count
}
s = t;
}
return s;
}
}