#include void str_add(char* a,char* b){ int i=0; while(a[i] && b[i]) { printf("%c%c", a[i],b[i]); i++; } if(a[i]) printf("%s\n", a+i); if(b[i]) printf("%s\n", b+i);}int main(){ str_add("abcd", "ABCDEFG"); str_add("ABCDEFG","abcd");}