题目链接:http://codeforces.com/contest/351/problem/A 算法思路:2n个整数,一半向上取整,一半向下.我们设2n个整数的小数部分和为sum. ans = |A - B|; sum = A +(n-b)-B; 所以ans = |sum - (n-b) |; 只有b未知,只需要枚举一下b就得到答案. #include<cstdio> #include<iostream> #include<algorithm> #include<…

C. Jeff and Rounding time limit per test:  1 second memory limit per test: 256 megabytes input: standard input output: standard output Jeff got 2n real numbers a1, a2, ..., a2n as a birthday present. The boy hates non-integer numbers, so he decided t…

题意 有一个含有\(2n(n \leqslant2000)\)个实数的数列,取出\(n\)个向上取整,另\(n\)个向下取整.问取整后数列的和与原数列的和的差的绝对值. 就是说,令\(a\)为原数列,\(b\)为取整后数列,求 \[ min(abs(\sum_{i=1}^{2n}a-\sum_{i=1}^{2n}b)) \] 解题思路 刚开始大力猜了一波贪心结论,然后怒WA n发-- 我也不知道怎么会想到以下这个奇怪的结论的-- 如果我们设\(n\)个被向上取整的数的小数部分的和为\(a\)(其…

http://codeforces.com/problemset/problem/351/A 题意: 2*n个数,选n个数上取整,n个数下取整 最小化 abs(取整之后数的和-原来数的和) 先使所有的数都下取整,累积更改的sum 那么选1个小数上取整,就会使sum-1 整数上下取整不会产生影响 所以有1个整数就可以使上取整的小数少1个 所以ans=min(abs(i-sum)) i∈[n-整数个数,n] #include<cmath> #include<cstdio> #inclu…

C. Jeff and Rounding time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Jeff got 2n real numbers a1, a2, ..., a2n as a birthday present. The boy hates non-integer numbers, so he decided to sli…

题目连接:Codeforces 437C  The Child and Toy 贪心,每条绳子都是须要割断的,那就先割断最大值相应的那部分周围的绳子. #include <iostream> #include <cstring> #include <cstdio> #include <algorithm> using namespace std; const int MAX_N = 1000 + 10; int G[MAX_N][MAX_N]; struct…

https://codeforces.com/contest/1136/problem/D 贪心 + 思维 题意 你面前有一个队列,加上你有n个人(n<=3e5),有m(m<=个交换法则,假如u在v相邻前面,那么u和v可以交换位置,问你是队列最后一个人的时候你最前可以换到前面哪里 题解 因为相邻才能换,所以最后一个换到前面一定是一步一步向前走,所以不存在还要向后走的情况 设最后一个为u,假设前面有一个能和u换位置的集合,那么需要将这些点尽量往后移动去接u 假设前面有一个不能和u换位置的集合S,…

给予N*2个数字,改变其中的N个向上进位,N个向下进位,使最后得到得数与原来数的差的绝对值最小 考虑小数点后面的数字,如果这些数都非零,则就是  abs(原数小数部分相加-1*n), 多一个0 则 min( abs(原数小数部分相加-1*n) ,abs(原数小数部分相加-1*(n-1)) )以此类推 #include<stdio.h> int abs(int a){ )return -a; else return a; } int Min(int a,int b){ if(a<b)ret…

http://codeforces.com/contest/738/problem/D Galya is playing one-dimensional Sea Battle on a 1 × n grid. In this game a ships are placed on the grid. Each of the ships consists of bconsecutive cells. No cell can be part of two ships, however, the shi…

C. Load Balancing 题目连接: http://www.codeforces.com/contest/609/problem/C Description In the school computer room there are n servers which are responsible for processing several computing tasks. You know the number of scheduled tasks for each server:…