#include <stdio.h>
#include <string.h>
void MergeString(char s[],char s1[],char s2[])
{
	int i = 0;
	char *p,*q;
	p = s1;
	q = s2;
	while(*q != '\0') q++;
	q--;
	while(*p != '\0' || *q != '\0')
		if(i % 2 == 0) s[i++] = *p++;
		else s[i++] = *q--;
	s[i] = '\0';
}
...