time limit per test2 seconds memory limit per test256 megabytes inputstandard input outputstandard output After overcoming the stairs Dasha came to classes. She needed to write a password to begin her classes. The password is a string of length n whi…

题目链接 Dasha and Password 题目保证一定有解. 考虑到最多只有两行的指针需要移动,那么直接预处理出该行移动到字母数字或特殊符号的最小花费. 然后O(N^3)枚举求最小值即可. 时间复杂度O(N*M+N^3) #include <bits/stdc++.h> using namespace std; #define REP(i,n) for(int i(0); i < (n); ++i) #define rep(i,a,b) for(int i(a); i <=…

题目链接:http://codeforces.com/problemset/problem/761/C C. Dasha and Password time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output After overcoming the stairs Dasha came to classes. She needed to w…

C. Dasha and Password 题目连接: http://codeforces.com/contest/761/problem/C Description After overcoming the stairs Dasha came to classes. She needed to write a password to begin her classes. The password is a string of length n which satisfies the follo…

C. Dasha and Password time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output After overcoming the stairs Dasha came to classes. She needed to write a password to begin her classes. The password i…

C. Dasha and Password time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output After overcoming the stairs Dasha came to classes. She needed to write a password to begin her classes. The password i…

题目:http://codeforces.com/gym/100338/attachments 贪心,每次枚举10的i次幂,除k后取余数r在用k-r补在10的幂上作为候选答案. #include<bits/stdc++.h> using namespace std; typedef unsigned long long ull; ; ull base[maxbit], n, k; void preDeal() { ] = ; ; i < maxbit; i++){ *]; } } voi…

[Codeforces 1214A]Optimal Currency Exchange(贪心) 题面 题面较长,略 分析 这个A题稍微有点思维难度,比赛的时候被孙了一下 贪心的思路是,我们换面值越小的货币越优.如有1,2,5,10,20,50,那么我们尽量用面值为1的.如果我们把原始货币换成面值为x的货币,设汇率为d,那么需要的原始货币为dx的倍数.显然dx越小,剩下的钱,即n取模dx会尽量小. 然后就可以枚举换某一种货币的数量,时间复杂度\(O(\frac{n}{d})\) 代码 #inclu…

C. Dasha and Password time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output After overcoming the stairs Dasha came to classes. She needed to write a password to begin her classes. The password i…

看题传送门:http://poj.org/problem?id=1018 题目大意: 某公司要建立一套通信系统,该通信系统需要n种设备,而每种设备分别可以有m个厂家提供生产,而每个厂家生产的同种设备都会存在两个方面的差别:带宽bandwidths 和 价格prices. 现在每种设备都各需要1个,考虑到性价比问题,要求所挑选出来的n件设备,要使得B/P最大. 其中B为这n件设备的带宽的最小值,P为这n件设备的总价. 思路: 贪心+枚举 要使得B/P最大,则B应该尽量大,而P尽量小. 可以按照价格…