Leetcode#38count and Say

The Count-and-say sequence is the sequence of integers beginning as follows:
1, 11, 21, 1211, 111221, ...

1is read off as"one 1"Or11.
11is read off as"two 1s"Or21.
21is read off as"one 2, thenone 1"Or1211.

Given an integer n, generate the nth sequence.

Note:the sequence of integers would be represented as a string.

Analysis, the iteration solves the result of nth time, so starting with the first "1" iteration, the last resulting string is re-expressed in the above form

public class Solution {

Public String Countandsay (int n) {

if (n = = 1) {

return "1";

}

String s = "1";

StringBuffer ret = new StringBuffer ();

int cnt = 0;

int round = 0; How many times round is an iteration

int i;

while (++round < n) {

CNT = 1;

Ret.setlength (0);

for (I=1; I<s.length (); i++) {

if (S.charat (i) = = S.charat (i-1)) {//duplicate value, continue count

cnt++;

}else{//A new value appears, recorded to RET

Ret.append (CNT). Append (S.charat (i-1));

CNT = 1; Reset CNT

}

}

Ret.append (CNT). Append (S.charat (i-1));

s = ret.tostring (); Update S

}

return ret.tostring ();

}

}

Leetcode#38count and Say