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.

题意怎么说就怎么做吧。暂时没找到更简便的方式。

public static String countAndSay(int n) {
if (n == 0) return null;
String[] nums = new String[n - 1];
nums[0] = "1";
for (int i = 0; i < n - 1; i++) {
int count = 0;
char num = nums[i].charAt(0);
StringBuffer say = new StringBuffer("");
for (int j = 0; j < nums[i].length(); j++) {
if (nums[i].charAt(j) == num)
count++;
else {
say.append(count).append(num);
num = nums[i].charAt(j);
count = 1;
}
}
nums[i + 1] = say.append(count).append(num).toString();
}
return nums[n - 1];
}