QQ空间滚动字幕怎么弄啊?

#include <stdio.h>
#include <time.h>
#include <conio.h>
#include <string.h>

#define TIME_INTERVAL (CLOCKS_PER_SEC / 50)

int main(int argc, char* argv[])
{
int i, j;
long c;
char str[80] = "Hello world!";
int l = strlen(str);
char sleft[80];
char sright[80];
int scrwidth = 79;

while (1)
{
for (i = 0; i <= scrwidth; i++)
{
if (i <= scrwidth - l)
{
c = clock();
for (j = 0; j < i; j++)
{
printf(" ");
}
printf("%s\r", str);
while (clock() - c <= TIME_INTERVAL)
;
} else
{
c = clock();
strcpy(sleft, str);
strcpy(sright, str + l - (i - (scrwidth - l)));
*(sleft + l - (i - (scrwidth - l))) = NULL;
for (j = 0; j < i; j++)
{
printf("