Problem A 拿出勇气吧 幸运数字每一位是$4$或者$7$,现在给出一个数字每位数位上数的和为n,求出最小的幸运数n 对于100%的数据,$n\leq 10^6$ Sol : 显然本题要求数的长度尽可能短,于是显然是先放$7$放$4$并且$7$放在较低位. 这就等价于求不定方程$4x + 7y = n $的最小整数解x,然后只要延续输出x个4,y个7即可. 只需要做一次exgcd就可以求出. 复杂度应该是答案的长度 $O(length)$ # include <bits/stdc++.h>…
Fleeting time does not blur my memory of you. Can it really be 4 years since I first saw you? I still remember, vividly, on the beautiful Zhuhai Campus, 4 years ago, from the moment I saw you smile, as you were walking out of the classroom and turned…
我要举报本次校赛出题人的消极出题!!! 官方题解请戳:http://3.scnuacm2015.sinaapp.com/?p=89(其实就是一堆代码没有题解) A. 树链剖分数据结构板题 题目大意:我没看,看不懂. 基本思路:我不会. 参考代码:找Oyk老师和Czj老师去. B. The background of water problem 题目大意(大写加粗的水题):给定$N$个学生和他们$K$个科目的成绩$S_i$,再给出各科目$K_i$的权重顺序$Q_i$,求排名之后,拥有id为$X$的…
Problems # Name A Infinite Sequence standard input/output 1 s, 256 MB x3509 B Restoring Painting standard input/output 1 s, 256 MB x2519 C Money Transfers standard input/output 1 s, 256 MB x724 D Tree Construction standard input/outp…