Count and Say Leetcode

Source: Internet
Author: User

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

1is read off as "one 1" or 11 .
11is read off as "two 1s" or 21 .
21is read off "one 2 as, then one 1" or 1211 .

Given an integer n, generate the nth sequence.

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

Test instructions is n=1 when the output string 1;n=2, the number of numbers in the last string, because the last string has a 1, so the output 11;n=3, because the last character is 11, there are 2 1, so the output 21;n=4, because the last string is 21, there is a 2 and a 1, So the output is 1211. Write a Countandsay (n) function to return the string, in turn.

Count and Say Leetcode

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