题目描述:
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。
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:
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
上代码,拿去即可运行:
package com.onlyqi.daydayupgo01.test;
public class Test20 {
public static void main(String[] args) {
char[]chars = {'h','e','l','l','o'};
reverseString(chars);
for (char aChar : chars) {
System.out.print(aChar+" ");
}
}
public static void reverseString(char[] s) {
if (s.length != 0) {
int first = 0;
int last = s.length - 1;
char num;
while (first<last){
num = s[first];
s[first] = s[last];
s[last] = num;
first++;
last--;
}
}
}
}
运行结果:
我要刷300道算法题,第123道 。 好久好久没写算法了,最近开始写,先从最简单的开始。希望自己可以坚持下去