纪念一下C++ 11中的to_string()

今天发现C++ 11中推出了一个非常有用的函数 to_string() , 非常有效的解决了C++中其他类型（数字）转换成string。咱们再也不用麻烦的使用stringstream去转换了。贴上一个code，Leetcode中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.

class Solution {
public:
string countAndSay(int n) {
int i=1;
string val=to_string(1);
while(i<n){
val=getSequence(val);
i++;
}
return val;
}

string getSequence(string val){
int cnt=1;
string newstr="";
int i;
for(i=0;i<val.length()-1;i++){
if(val[i+1]==val[i]) cnt++;
else{
newstr=newstr+to_string(cnt)+val[i]; //有木有看到这里闪亮的 to_string() !
cnt=1;
}
}
newstr=newstr+to_string(cnt)+val[i];
return newstr;
}
};

注意这里，nth个串意味着需要转换n-1次，而不是n次！