力扣:反转字符串
哔哩哔哩 2023-04-11 08:52:47
344. 反转字符串
难度简单750
编写一个函数,其作用是将输入的字符串反转过来。输入字符串以字符数组 s
的形式给出。
(相关资料图)
不要给另外的数组分配额外的空间,你必须原地修改输入数组、使用 O(1) 的额外空间解决这一问题。
示例 1:
输入:s = ["h","e","l","l","o"]输出:["o","l","l","e","h"]
示例 2:
输入:s = ["H","a","n","n","a","h"]输出:["h","a","n","n","a","H"]
提示:
1 <= s.length <= 105
s[i]
都是 ASCII 码表中的可打印字符
通过次数725,608提交次数911,425
第一种对法:
双指针法,时间复杂度O(n)
注意:记得迭代循环条件
class Solution {
public:
void reverseString(vector<char>& s) {
int left,right;
left = 0,right = s.size()-1;
while(left<right){
char tmp = s[left];
s[left] = s[right];
s[right] = tmp;
left++,right--;
}
}
};