LeetCode-38. 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.

这道题就是N次循环~然后每一次遍历一遍字符串即可。

public String countAndSay(int n) {
String str = "1";
int cnt = 1;
String temp = "";
int i = 1;
for(int j = 0; j < n-1; j++){
char[] ch = str.toCharArray();
for(i = 1; i < str.length(); i++){
if(ch[i-1] == ch[i]){
cnt++;
}else{
temp = temp + cnt + ch[i-1];
cnt = 1;
}
}
temp = temp + cnt + ch[i-1];
str=temp;

temp = "";
cnt = 1;
}
return str;
}