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.
博主没睡醒。。。自己给该题增加的难度。。。可以从n开始n，1n...不一定从1，11，21... 但是思路是一样的
package leetcode2; public class CountandSay { public static String countSay(int n){ // return count(n,n) ; String[] s=new String[n]; s[0]=""+n; String sub=s[0]; // System.out.println(s[0]); for(int j1=1;j1<n;j1++){ StringBuilder snext=new StringBuilder(); int i=1; int count=1; while(i<sub.length()){ if(sub.charAt(i)==sub.charAt(i-1)){ count++; i++; }else{ snext=snext.append(count); snext=snext.append(sub.charAt(i-1)); i++; count=1; } } snext=snext.append(count); snext=snext.append(sub.charAt(i-1)); sub=snext.toString(); } return sub; } public static void main(String[] args) { // TODO Auto-generated method stub System.out.print(countSay(4)); } }
原文：http://www.cnblogs.com/joannacode/p/4391439.html