1294 - Positive Negative Sign(规律)
Time Limit: 2 second(s) | Memory Limit: 32 MB |
Given two integers: n and m and n is divisible by 2m, you have to write down the first n natural numbers in the following form. At first take first m integers and make their sign negative, then take next m integers and make their sign positive, the next m integers should have negative signs and continue this procedure until all the n integers have been assigned a sign. For example, let n be 12 and m be 3. Then we have
-1 -2 -3 +4 +5 +6 -7 -8 -9 +10 +11 +12
If n = 4 and m = 1, then we have
-1 +2 -3 +4
Now your task is to find the summation of the numbers considering their signs.
Input
Input starts with an integer T (≤ 10000), denoting the number of test cases.
Each case starts with a line containing two integers: n and m (2 ≤ n ≤ 109, 1 ≤ m). And you can assume that n is divisible by 2*m.
Output
For each case, print the case number and the summation.
Sample Input |
Output for Sample Input |
2 12 3 4 1 |
Case 1: 18 Case 2: 2 |
题解:这个规律比较好推,直接每隔m一正一负,依次相减就是m了,因为整除2*m,就直接是m*n/2;因为没有加case,wa了一次,还是太不细心了啊;
代码:
#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
#define mem(x,y) memset(x,y,sizeof(x))
using namespace std;
typedef long long LL;
const int INF=0x3f3f3f3f;
int main(){
int T,flot=;
LL n,m;
scanf("%d",&T);
while(T--){
scanf("%lld%lld",&n,&m);
printf("Case %d: %lld\n",++flot,m*(n/));
}
return ;
}
1294 - Positive Negative Sign(规律)的更多相关文章
- light oj 1294 - Positive Negative Sign
1294 - Positive Negative Sign PDF (English) Statistics Forum Time Limit: 2 second(s) Memory Limit: ...
- LightOJ - 1294 - Positive Negative Sign(规律)
链接: https://vjudge.net/problem/LightOJ-1294 题意: Given two integers: n and m and n is divisible by 2m ...
- lightoj--1294--Positive Negative Sign(水题,规律)
Positive Negative Sign Time Limit: 2000MS Memory Limit: 32768KB 64bit IO Format: %lld & %llu ...
- 阳/阴性预测值Positive/negative Predictive Value(推荐AA)
sklearn实战-乳腺癌细胞数据挖掘(博主亲自录制视频教程) https://study.163.com/course/introduction.htm?courseId=1005269003&am ...
- 智课雅思短语---二、exert positive/ negative effects on…
智课雅思短语---二.exert positive/ negative effects on… 一.总结 一句话总结:对…产生有利/不利的影响 1.the advantages far outweig ...
- 零宽断言 -- Lookahead/Lookahead Positive/Negative
http://www.vaikan.com/regular-expression-to-match-string-not-containing-a-word/ 经常我们会遇到想找出不包含某个字符串的文 ...
- Amazon评论数据的预处理代码(Positive & Negative)
Amazon评论数据的预处理代码,用于情感分析,代码改自 https://github.com/PaddlePaddle/Paddle/tree/develop/demo/quick_start/da ...
- [LeetCode] Valid Number 验证数字
Validate if a given string is numeric. Some examples:"0" => true" 0.1 " => ...
- [leetcode]65. Valid Number 有效数值
Validate if a given string can be interpreted as a decimal number. Some examples:"0" => ...
随机推荐
- zoj 1453 Stripies
/* 根据题意:不难看出,要是整个方程式最小,那么应该大的数先结合,小的数后结合.先排序然后结合(贪心) */ #include<stdio.h> #include<stdlib.h ...
- C++ STL中map存储方式——SAP电面(4)
map存储方式 一般是平衡二叉树 红黑树
- [NewCoder]复杂链表的复制
看下面一个链表结点的定义: struct ComplexListNode { int val; struct ComplexListNode *next; struct ComplexListNode ...
- 常用类库之.NET中的字符串
字符串的特性 .不可变性 由于字符串是不可变的的,每次修改字符串,都是创建了一个单独字符串副本(拷贝了一个字符串副本).之所以发生改变只是因为指向了一块新的地址. .字符串池(只针对字符串常量) 当一 ...
- [LeetCode]题解(python):073-Set Matrix Zeroes
题目来源: https://leetcode.com/problems/set-matrix-zeroes/ 题意分析: 输入一个m×n矩阵,如果出现有0,那么将对应的行和列都变成0. 题目思路: 简 ...
- poj 2007 Scrambled Polygon 极角排序
/** 极角排序输出,,, 主要atan2(y,x) 容易失精度,,用 bool cmp(point a,point b){ 5 if(cross(a-tmp,b-tmp)>0) 6 retur ...
- 2_Cat Years
2 // // ViewController.swift // Cat Years // // Created by ZC on 16/1/6. // Copyright © 2016年 ZC. Al ...
- Ntop监控网络流量
运用Ntop监控网络流量 ____ 网络流量反映了网络的运行状态,是判别网络运行是否正常的关键数据,在实际的网络中,如果对网络流量控制得不好或发生网络拥塞,将会导致网络吞吐量下降. 网络性能降低.通过 ...
- 一个异或加密方案--C语言实现
核心代码: char encrypt( char f , char c) { return f^c; } int OutEncrypt( char *FilePath, char *SecretWor ...
- hdu3416 Marriage Match IV【最短路+最大流】
转载请注明出处,谢谢:http://www.cnblogs.com/KirisameMarisa/p/4297581.html ---by 墨染之樱花 题目链接:http://acm.hdu.ed ...