面試基礎_01字元串反轉操作

一 字元串按位元組反轉（this is a student ==> tneduts a si siht）

/************************************************************************* 
    > File Name: testStringByte.h
    > Author: qiaozp 
    > Mail: [email protected] 
    > Created Time: 2014-9-30 11:21:15
    > Attention: this is a student ===> tneduts a si siht
 ************************************************************************/ 
#include <iostream>
#include <string.h>
using namespace std;

void reverseByByte(char* p, char* e)
{
    //方法就是按位指派到目的字元串
    int i = 0;
    int size = strlen(p);
    e[size] = '\0';
    while((--size) >= 0)
    {
        e[i++] = p[size];
    }
}

int main()
{
    char* p = "you are a student!";
    char e[20] = {0};
    reverseByByte(p, e);
    cout << e << endl;
}
           

二 字元串按單詞反轉（this is a student ==> student a is this）

/************************************************************************* 
    > File Name: testStringWord.h
    > Author: qiaozp 
    > Mail: [email protected] 
    > Created Time: 2014-9-30 11:21:15
    > Attention: this is a student ===> student a is this
************************************************************************/ 
#include <iostream>
#include <string.h>
using namespace std;

void reverseByWord(char* p, char* e)
{
    //方法就是記錄每個整的單詞的開始和結束位置，然後拷貝到目标字元串
    int len = strlen(p);
    int end = len;
    int start = 0;
    memset(e, 0, len);

    while(len > 0)
    {
        end = len;
        while ((p[len - 1] != ' ') && (len > 0))
        {
            --len;
        };
        start = len--;
        strncpy(e + strlen(e), p + start, end - start);
        e[strlen(e)] = ' ';

    }
    e[strlen(e) - 1] = '\0';      //多出一個空格  謝謝二樓的提醒 
}

int main()
{
    char* p = "you are a student!";
    char e[20] = {0};
    reverseByWord(p, e);
    cout << e << endl;
}