题意:给定 n 个数,可以对所有的数进行缩小,问你找出和最大的数,使得这些数都能整除这些数中最小的那个数. 析:用前缀和来做,先统计前 i 个数中有有多少数,然后再进行暴力去找最大值,每次都遍历这一段就好. 代码如下: #pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string> #include <cstdlib> #inclu…

题意:给定n个数字,你可以从中选出一个数A(不能对该数进行修改操作),并对其它数减小至该数的倍数,统计总和.问总和最大是多少? 题解:排序后枚举每个数作为选出的数A,再枚举其他数, sum += a[i]-a[i]%A;复杂度为O(n^2), 爆炸. 显然应该降至O(nlogn). 枚举每个数a[i]做为A,再枚举A的倍数j即可, sum += j*(lower_bound(a, a+n, j+a[i])-lower_bound(a, a+n, j)); 那么此时复杂度为O(nlognlogn)…

http://codeforces.com/contest/731/problem/F 注意到一个事实,如果你要找一段区间中(从小到大的),有多少个数是能整除左端点L的,就是[L, R]这样.那么,很明显,把这个区间分段.分成[L, 2 * L - 1],因为这段区间中,都不大于等于L的两倍,这样就使得这段区间的贡献就是sum_number * L了. 就是中间有多少个数,每个数贡献一个L值.然后到枚举[2 * L, 3 * L - 1]这段区间,贡献的值就是sum_number * (2 *…

time limit per test1 second memory limit per test256 megabytes inputstandard input outputstandard output Little Vlad is fond of popular computer game Bota-2. Recently, the developers announced the new add-on named Bota-3. Of course, Vlad immediately…

题目链接:http://codeforces.com/contest/731/problem/F F. Video Cards time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Little Vlad is fond of popular computer game Bota-2. Recently, the developers…

题目传送门 /* 数论/暴力:找出第一次到a1,a2的次数,再找到完整周期p1,p2,然后以2*m为范围 t1,t2为各自起点开始“赛跑”,谁落后谁加一个周期,等到t1 == t2结束 详细解释:http://blog.csdn.net/u014357885/article/details/46044287 */ #include <cstdio> #include <algorithm> #include <cstring> #include <iostream…

Codeforces 731 F. Video Cards 题目大意:给一组数,从中选一个数作lead,要求其他所有数减少为其倍数,再求和.问所求和的最大值. 思路:统计每个数字出现的个数,再做前缀和,用于之后快速求和.将原数组排序后去重,枚举每一个数做lead的情况下,其余数减少后再求和的结果.不断维护最大值即可. PS:这里用到了一个方便的函数unique()来去重,使用前需要先将数组排序,参数为数组的首地址和尾后地址,返回新的尾后地址.(该函数没有将重复的元素删除,只是放到了尾地址后面)可…

F. Video Cards time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Little Vlad is fond of popular computer game Bota-2. Recently, the developers announced the new add-on named Bota-3. Of course…

Video Cards time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Little Vlad is fond of popular computer game Bota-2. Recently, the developers announced the new add-on named Bota-3. Of course, V…

[CodeForces - 1225C]p-binary [数论][二进制] 标签: 题解 codeforces题解 数论 题目描述 Time limit 2000 ms Memory limit 524288 kB Source Technocup 2020 - Elimination Round 2 Tags bitmasks brute force math *1600 Site https://codeforces.com/problemset/problem/1225/c 题面 Exa…