It is already well-known that using unordered series in Codeforces is super dangerous, and it is not recommended to use them at all unless you know how to prevent them properly (well, even if you know, just using a regular map or set is more beneficial in most cases). Thanks to ...
Hey Codeforces I am well aware that we shouldn't use unordered maps in our solutions because they lead to tle in certain cases I came across some solutions using unordered map for the 4th Question in the recent Edu Round. I tried generating a testcase in which these submissions tle but fa...
就可以避免针对默认参数的hack,同时unordered_map的速度可以提升约10倍。 当然平时还是别偷懒加上快读快写,希望人别被卡 ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); 更多的关于unordered_map的细节可以学习cf大佬blog的评论区 https://codeforces.com/blog/entry/21853codefo...
但在Codeforces 的比赛上面,尽量别用unoredered_set / unoredered_map。 一是因为unordered_map本身自带大常数,有时候跑的甚至没有map快。 第二个原因也是最重要的原因是,很多 CF 上的大神直接根据 STL 的源代码来造出 hack 数据,导致单次复杂度劣化成O(n)O(n)。 如果你很勇直接用 unordered_map 那么你就...
记得在codeforces上交代码的时候大佬们会对使用unordered_set/unordered_map 的代码进行Hack,过程参考如下文章: Blowing up unordered_map, and how to stop getting hacked on it - Codeforcescodeforces.com/blog/entry/62393 其实也是利用了位置是哈希对桶数取模这一点。GCC的unordered_set/unordered_map 桶数...
然后下图中,上面的是采用map,下面的采用unordered_map 可以看到,无论空间和时间都是unordered后优秀。 Hack It! 我们用前面说过的那个卡掉代码的质数来做输入文件。输入的数字为126271的1～200000倍。然后分别使用map和unordered_map 来跑。看看结果怎样?(在其他oj创建的题目,速度应该也差不多) ...
This caused me think about which situations I should use an unordered_map instead of a regular map (ordered map). Is an unordered_map always inherently faster than a map? in which cases should I use it? I'm asking here because I couldn't get a satisfactory answer after searching the we...
可以，但不建议。unordered_map容易被卡，参考codeforces比赛。要么重新散列函数，要么直接用map、set吧据...
, when I used set it gave TLE on test case 10 but when I used unordered_set, it got Accepted. I read some blogs where they told not to use unordered_set/map on CF as it can be hacked, so what should I do, should I use unordered set/map or not?