Given a string and an integer k, you need to reverse the first k characters for every 2k characters counting from the start of the string. If there are less than k characters left, reverse all of them. If there are less than 2k but greater than or equal to k characters, then reverse the first k characters and left the other as original.
Example:
Input: s = “abcdefg”, k = 2
Output: “bacdfeg”
Restrictions:
The string consists of lower English letters only.
Length of the given string and k will in the range [1, 10000]
class Solution {
public:
string reverseStr(string s, int k) {
int i = 0 ;
while(i < s.size()){
if(i+k<=s.size()){
reverse(s.begin()+i,s.begin()+i+k);
}
else{
reverse(s.begin() + i,s.end());
}
i+=2*k;
}
return s;
}
};