- A
n*m/2. - B
Record the occurrences' number of each letters, signed as cnt[char].
For each char in string, get the cnt[c]^2 plus together, and this is the answer. - C
Calculate the Convex Hull.
The sum of the max value between x-difference and y-difference of each adjacent points in the convex hull's set and 4 is the answer.
4 step can make a circle of 360 degree. - D
Counting the answer with Half, and check the answer using Dynamic Programming.
Let dp[i][j] means the probability of first i objects where j of them exploded, and the transfering formular is:
dp[i][j] = P(i) * dp[i - 1][j - 1] + (1 - P(i)) * dp[i - 1][j], where P(i) means the i-th object exploding's probability.
→ Pay attention
→ Streams
→ Top rated
| # | User | Rating |
|---|---|---|
| 1 | tourist | 3985 |
| 2 | jiangly | 3814 |
| 3 | jqdai0815 | 3682 |
| 4 | Benq | 3529 |
| 5 | orzdevinwang | 3526 |
| 6 | ksun48 | 3517 |
| 7 | Radewoosh | 3410 |
| 8 | hos.lyric | 3399 |
| 9 | ecnerwala | 3392 |
| 9 | Um_nik | 3392 |
→ Top contributors
| # | User | Contrib. |
|---|---|---|
| 1 | cry | 169 |
| 2 | maomao90 | 162 |
| 2 | Um_nik | 162 |
| 4 | atcoder_official | 161 |
| 5 | djm03178 | 158 |
| 6 | -is-this-fft- | 157 |
| 7 | adamant | 155 |
| 8 | awoo | 154 |
| 8 | Dominater069 | 154 |
| 10 | luogu_official | 150 |
→ Find user
→ Recent actions
Tutorial of Codeforces Beta Round 47
Codeforces (c) Copyright 2010-2024 Mike Mirzayanov
The only programming contests Web 2.0 platform
Server time: Dec/23/2024 02:45:09 (i1).
Desktop version, switch to mobile version.
Supported by
