倒数第N个字符串

int main(){
  int l, n, i, k = 0, t;
  int a[10];
  cin>>l>>n;
  --n;// 第n个就是下标为n-1
  while (n){
    t = n % 26;
    if (t) a[k++] = t;
    else a[k++] = 0;
    n /= 26;
  }
  for (; k < l; ++k)a[k] = 0;
  for (i = k - 1; i >= 0; --i){
    printf("%c", 25 - a[i] + 'a');
  }
  printf("
");
  return 0;
}

int main(){
  int L,N;
  int a[10];
  scanf("%d %d",&L,&N);
  N--;
  int flag=0;
  while(N>0){
    a[++flag]=N%26;
    N=N/26;
  }
  for(int i=1;i<=L-flag;i++){
    printf("z");
  }
  for(int i=flag;i>=1;i--){
    printf("%c",'z'-a[i]);
  }
  return 0;
}