C :

#include<stdio.h>
#include<string.h>
int main()
{
	char a[1000],b[1000]={NULL};
	gets(a);
	int len=strlen(a);
	a[len]=' ';
	a[len+1]='\0';
	for(int i=len-1;i>=0;i--)
	{
		if(a[i]==' ')
		{
			strcat(b,a+i+1);
			a[i+1]='\0';
		}
	}
	strcat(b,a);
	puts(b);
}

C++ :

#include <stdio.h>
#include <stdlib.h>
#include<iostream>
#include <cstring>
using namespace std;

void ReverseWord(char* p, char* q)
{
    while(p < q)
    {
        char t = *p ;
        *p++ = *q ;
        *q-- = t ;
	}
}
char* ReverseSentence(char* s)
{
    char* p = s ;
	char* q = s ;

    while(*q != '\0')
    {
        if (*q == ' ')
        {
            ReverseWord(p, q - 1) ;
            q++ ; 
            p = q ;
        }
        else
            q++ ;
	}
    ReverseWord(p, q - 1) ; 
    ReverseWord(s, q - 1) ; 
    return s ;
}
int main(){
	char a[2001];
	gets(a);
	printf("%s\n",ReverseSentence(a));
	
	return 0;
}

Python :

# coding=utf-8
s=input()
lst=s.split()
for i in range(len(lst),0,-1):
    print(lst[i-1],end="")
    if i!=1:
        print(" ",end="")