#include <iostream>
using namespace std;
#define SWAP(x, y) (x)^=(y)^=(x)^=(y)
void Reverse(char* str)
{
    char *start=str, *end = str;
    while (*end)
    {
        while (*end && *end != ' ') ++end;
        for (char* s = start, *e = end-1; s < e; ++s, --e)
            SWAP(*s, *e);
        while (*end && *end == ' ') ++end;
        start = end;
    }
    for (start = str, --end; start < end; ++start, --end)
        SWAP(*start, *end);
}
int main() 
{ 
    char str[] = "i am a student";
    Reverse(str);
    printf("%s\n", str);
    return 0; 
} 

/* inversewords.c
*  把一个字符串单词倒序,例如"I am a student"转变后"student a am I".
*/

void strInverse(char str[]);

int main(int argc,char *argv[])
{
    char c[] = "I like C";
    int i;
    
    if(argc > 1)
    {
        for(i = (argc-1);i > 0;i--)
        {
              printf("%s ",argv[i]);
        }
    }
    else
    {
          printf("%s\n",c);    
    }
    
    return 0;
}

/* inversewords.c
*  把一个字符串单词倒序,例如"I am a student"转变后"student a am I".
*/

#include <stdio.h>
#include <stdlib.h>

int main(int argc,char *argv[])
{
    char c[] = "I like C";
    char *p;
    int i;
    
    p = c;
    
    if(argc > 1)
    {
        for(i = (argc-1);i > 0;i--)
        {
            p = realloc(p,(strlen(argv[i]) + strlen(p)));
            sprintf(p,"%s ",argv[i]);
            printf("%s",p);
        }
    }
    else
    {
          printf("%s\n",c);    
    }
    
    return 0;
}

/* inversewords.c
*  把一个字符串单词倒序,例如"I am a student"转变后"student a am I".
*/

#include <stdio.h>
#include <stdlib.h>

int main(int argc,char *argv[])
{
    char temp[100];
    char *p;
    int i;
    int iLen = 0;
    
    p = malloc(sizeof(char *));

    if(argc > 1)
    {    
         iLen = sizeof(p) - strlen(p);
           memset(p,'\0',sizeof(p));
           
        for(i = (argc - 1);i > 0;i--)
        {
            memset(temp,'\0',sizeof(temp));
            iLen = iLen + strlen(argv[i]) + 1;
            
            p = realloc(p,iLen);
            sprintf(temp,"%s ",argv[i]);
            strcat(p,temp);
        }
        
        p[iLen - 1] = '\0';
        printf("%s",p);
    }
    else
    {
          printf("Please input the data.\n");    
    }
    
    return 0;
}

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

void foo(char* str)
{
    int length = strlen(str);
    int offset = 0;
    char* result= (char*)malloc(length);
    int wordlen = 0;
    for(int i=length-1;i>=0;--i)
    {
        if(str[i] != ' ')
        {
            ++wordlen;
        }
        else
        {
            memcpy(result+offset,str+i+1,wordlen);
            result[offset+wordlen] = ' ';
            offset += wordlen+1;
            wordlen = 0;
        }            
    }
    memcpy(result+offset,str,wordlen);
    memcpy(str,result,length);
}
void main()
{
    char buf[] = "I am a student";
    foo(buf);
    printf(buf);
}

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

void foo(char* str)
{
    int length = strlen(str);
    int offset = 0;
    char* result= (char*)malloc(length);
    int wordlen = 0;
    for(int i=length-1;i>=0;--i)
    {
        if(str[i] != ' ')
        {
            ++wordlen;
        }
        else
        {
            memcpy(result+offset,str+i+1,wordlen);
            result[offset+wordlen] = ' ';
            offset += wordlen+1;
            wordlen = 0;
        }            
    }
    memcpy(result+offset,str,wordlen);
    memcpy(str,result,length);
    free(result);
}
void main()
{
    char buf[] = "I am a student";
    foo(buf);
    printf(buf);
}