I tried to use google translator, but still can't understand this problem statement. Can someone translate/explain this problem?

Link: https://atcoder.jp/contests/typical90/tasks/typical90_o

# | User | Rating |
---|---|---|

1 | Benq | 3796 |

2 | tourist | 3722 |

3 | Radewoosh | 3719 |

4 | ecnerwala | 3578 |

5 | ksun48 | 3462 |

6 | Um_nik | 3456 |

7 | maroonrk | 3445 |

8 | jiangly | 3431 |

9 | Petr | 3370 |

10 | scott_wu | 3350 |

# | User | Contrib. |
---|---|---|

1 | 1-gon | 208 |

2 | awoo | 186 |

3 | rng_58 | 184 |

4 | Errichto | 182 |

5 | SecondThread | 178 |

6 | Radewoosh | 177 |

7 | -is-this-fft- | 176 |

7 | maroonrk | 176 |

9 | Um_nik | 173 |

10 | antontrygubO_o | 170 |

I tried to use google translator, but still can't understand this problem statement. Can someone translate/explain this problem?

Link: https://atcoder.jp/contests/typical90/tasks/typical90_o

↑

↓

Codeforces (c) Copyright 2010-2021 Mike Mirzayanov

The only programming contests Web 2.0 platform

Server time: Jun/14/2021 21:31:01 (g1).

Desktop version, switch to mobile version.

Supported by

User lists

Name |
---|

Problem statement:

There are N pieces of balls where 1-N number are written on them.

Then answer the following question for every k between 1-N.

-How many ways can you choose a set of ball where the absolute difference of the every ball pair's number is equal or greater than k. However, the answer can be very large, so output the result after mod 10e9+7.

Constraint:

1≤N≤10^5 N is an integer

Thanks!

So just to understand this problem a bit more precise, if N=3 and I have a set of balls {1,2,3} that would result in a difference of 1? And if I have sets like {1}, {2}, ... , {N} a difference of those would be +INF?

I think N=3 case looks like this:

k=1 -> answer {1,2,3}, {1,2}, {2,3}, {1,3}

k=2 -> answer {1, 3}

{1, 2} can't be an answer, diff(1,2) = 1 < k

k=3 -> no answer

but if you look at Sample 3, for N=3 the answer is 7,4,3. Thus I guess that {1},{2},{3} are always present for any k, and your mentioned sets are added on top of that so: 4+3=7, 1+3=4, 0+3=3