LeetCode 344.Reverse String

Write a function that takes a string as input and returns the string reversed.

Example:
Given s = “hello”, return “olleh”.

https://leetcode.com/problems/reverse-string/

答案
C（用库函数）

char* reverseString(char* s) {
int len = strlen(s);
char temp;
for(int i=0; i<len/2; i++){
    temp=s[i];
    s[i]=s[len-1-i];
    s[len-1-i]=temp;
}
    return s;
}

C（不用库函数）

#include<stdio.h>

char* reverseString(char* s);
int strLen(char* s);

void main()
{
    char str[100000] = "";

    printf("%s", reverseString(str));
}

char* reverseString(char* s) {
    if(s == NULL)
        return 0;

    char *str = s;
    char *begin = s;
    char *end = s + strLen(str);
    char temp;

    while(begin < end) {
        temp = *begin;
        *begin = *end;
        *end = temp;

        begin++;
        end--;
    }

    return str+1;
}

int strLen(char* s){
    char *eos = s;
    while(*eos++);
    return(eos-s-1);
}

Java

class Solution {
    private String s;
        public String reverseString(String s) {
        this.s = s;
        StringBuffer zs = new StringBuffer();
        char rs;
        for (int i=0; i<s.length(); i++ ) {
        rs = s.charAt(s.length()-i-1 );
        zs.append(rs);
        }
        String ds = zs.toString();
        return ds;
    }
}