标签：fun while http mem href tmp wiki inpu The
344. Reverse String
Write a function that reverses a string. The input string is given as an array of characters char[].
Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.
You may assume all the characters consist of printable ascii characters.
Example 1:
Input: ["h","e","l","l","o"]
Output: ["o","l","l","e","h"]
Example 2:
Input: ["H","a","n","n","a","h"]
Output: ["h","a","n","n","a","H"]
package leetcode.easy;
public class ReverseString {
private static void print_arr(char[] s) {
for (int i = 0; i < s.length; i++) {
System.out.print(s[i] + " ");
}
System.out.println();
}
public void helper(char[] s, int left, int right) {
if (left >= right) {
return;
}
char tmp = s[left];
s[left++] = s[right];
s[right--] = tmp;
helper(s, left, right);
}
public void reverseString1(char[] s) {
helper(s, 0, s.length - 1);
}
public void reverseString2(char[] s) {
int left = 0, right = s.length - 1;
while (left < right) {
char tmp = s[left];
s[left++] = s[right];
s[right--] = tmp;
}
}
@org.junit.Test
public void test1() {
char[] s1 = { ‘h‘, ‘e‘, ‘l‘, ‘l‘, ‘o‘ };
char[] s2 = { ‘H‘, ‘a‘, ‘n‘, ‘n‘, ‘a‘, ‘h‘ };
print_arr(s1);
reverseString1(s1);
print_arr(s1);
print_arr(s2);
reverseString1(s2);
print_arr(s2);
}
@org.junit.Test
public void test2() {
char[] s1 = { ‘h‘, ‘e‘, ‘l‘, ‘l‘, ‘o‘ };
char[] s2 = { ‘H‘, ‘a‘, ‘n‘, ‘n‘, ‘a‘, ‘h‘ };
print_arr(s1);
reverseString1(s1);
print_arr(s1);
print_arr(s2);
reverseString1(s2);
print_arr(s2);
}
}
标签：fun while http mem href tmp wiki inpu The
原文地址：https://www.cnblogs.com/denggelin/p/11824008.html
