bool findSomething() {
  for (i=0; i < MAX; i++) {
    for (j=0; j < MAX; j++){
      if (a[i]!=a[j] && (a[i]+a[j] == x)){
        return true;
      }
  }
  return false; //C99 has boolean, yes
}

if (findSomething()) {
} else {
}