https://leetcode.com/problems/count-and-say/
题目:
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.
思路:
题意有些模糊,看明白1211到111221就懂了。
AC代码:
1 class Solution { 2 public: 3 string countAndSay(int n) { 4 int tmp_n,count,k; 5 string tmp,tmp_res,a[n]; 6 a[0]="1"; 7 for(int i=1;i<n;i++){ 8 tmp=a[i-1]; 9 tmp_res=""; 10 tmp_n=tmp.size(); 11 k=0; 12 count=1; 13 for(int j=1;j<tmp_n;j++){ 14 if(tmp[j]==tmp[j-1]){ 15 count++; 16 continue; 17 } 18 else{ 19 tmp_res.push_back('0'+count); 20 tmp_res.push_back(tmp[j-1]); 21 count=1; 22 } 23 } 24 tmp_res.push_back('0'+count); 25 tmp_res.push_back(tmp[tmp_n-1]); 26 a[i]=tmp_res; 27 } 28 return a[n-1]; 29 } 30 };