UIT 9.05

char* myStrcat(char *s1, char *s2){
    char *ans = NULL;
    ans = new char[MAX + MAX];
    int i = 0;
    while (s1[i]!='\0' && s1[i]!='\n') ans[i] = s1[i], i++;
    ans[i] = ' ';
    for(int k=0; ; k++){
        if (s2[k]=='\0' || s2[k]=='\n') break;
        ans[i + k] = s2[k];
    }
    return ans;
}