题 题意 两个数列,一个有n个数,另一个有m个数,让你最多交换两次两个数列的数,使得两个数列和的差的绝对值最小,求这个差的绝对值.最少交换次数.交换数对 分析 交换0次.1次可得到的最小的差可以枚举出来. 交换两次,如果枚举就超时了. 我们预处理把第一个数列两两组合的所有情况存储起来为u数组,并且按照大小排序,接着在另一个数列里枚举两个数后,用二分的方法,求交换后使得 差的绝对值最小 的u. 二分查找最接近的值可以用lower_bound函数. 代码 #include<stdio.h> #in…

Professor GukiZ and Two Arrays 题解: 将a数组都sort一遍之后, b数组也sort一遍之后. 可以观察得到 对于每一个ai来说, 整个数组bi是一个V型的. 并且对于ai+1的最优解一定是在ai的右边. 然后我们将a数组 和 b数组枚举一遍. 然后再将a数组22组合, b数组22组合之后, 再枚举一遍. 代码: #include<bits/stdc++.h> using namespace std; #define Fopen freopen("_i…

[codeforces 415D]Mashmokh and ACM 题意:美丽数列定义:对于数列中的每一个i都满足:arr[i+1]%arr[i]==0 输入n,k(1<=n,k<=2000),问满足[数列长度是k && 数列中每一个元素arr[i]在1~n之间 && 数列中元素可以重复]的数列有多少个?结果对10^9+7取余 解题思路:dp[i][j]表示长度是j,最后一位是i的种数 if(kk%i==0) dp[kk][j+1]+=dp[i][j] #inc…

D. Professor GukiZ and Two Arrays 题目连接: http://www.codeforces.com/contest/620/problem/D Description Professor GukiZ has two arrays of integers, a and b. Professor wants to make the sum of the elements in the array a sa as close as possible to the sum…

Professor GukiZ and Two Arrays 题意:两个长度在2000的-1e9~1e9的两个序列a,b(无序);要你最多两次交换元素,使得交换元素后两序列和的差值的绝对值最小:输出这个最小的和的差值的绝对值:并且输出交换次数和交换的序号(从1 开始) Input 5 5 4 3 2 1 4 1 1 1 1 Output 1 2 1 1 4 2 策略: 若是只交换一次,直接O(n^2)暴力即可:但是里面可以交换两次..若是分开看..没思路.那就开始时就预处理出同一个序列中任意两个…

time limit per test2 seconds memory limit per test256 megabytes inputstandard input outputstandard output Professor GukiZ is concerned about making his way to school, because massive piles of boxes are blocking his way. In total there are n piles of…

time limit per test2 seconds memory limit per test256 megabytes inputstandard input outputstandard output Professor GukiZ likes programming contests. He especially likes to rate his students on the contests he prepares. Now, he has decided to prepare…

time limit per test2 seconds memory limit per test256 megabytes inputstandard input outputstandard output Professor GukiZ doesn't accept string as they are. He likes to swap some letters in string to obtain a new one. GukiZ has strings a, b, and c. H…

time limit per test2 seconds memory limit per test512 megabytes inputstandard input outputstandard output Bash has set out on a journey to become the greatest Pokemon master. To get his first Pokemon, he went to Professor Zulu's Lab. Since Bash is Pr…

[题目链接]:http://codeforces.com/contest/707/problem/E [题意] 给你一个n*m的方阵; 里面有k个联通块; 这k个联通块,每个连通块里面都是灯; 给你q个操作; 有以下两种类型 ①将第i个连通块里面灯取反 ②询问你(x1,y1)(x2,y2)这个矩形区域内灯的权值的和; [题解] 要用到二维的树状数组; 取反操作只要O(1)就能完成; 即先不管它是什么,取反就是了; 然后在询问的时候,直接用二维树状数组累加; 这里的累加可能是减也可能是加; 也可能…