题目来源【Leetcode】
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]
这道题就是考虑好最后剩下的那部分的转化就没啥问题了
class Solution {
public:
string reverseStr(string& s, int k) {
int l = s.length();
if(l < k) {
reverse(&s[0],&s[l]);
return s;
}
int i = 0;
while(i < l && l-i >= k){
int end = i+k-1;
cout<<i<<" "<<end<<endl;
reverse(&s[i],&s[i+k]);
i += 2*k;
}
reverse(&s[i],&s[l]);
return s;
}
};