题意: 就是有n个点,本来相邻点之间就有一条边,1和n之间也有一条,然后给你几个特殊点,说这些特殊点和其他所有点都连起来了,然后算一个所有边的权值和,每条边的权值等于两个点的c相乘. 思路: 水题啊-感觉有好多方法吧.弱的思路:你把所有点都相连的情况,把所有边权值和算出来,然后没有被标记的点拿出来,把他们两两相连的边的权值也减掉,但是你会发现就算没有标记但是相邻还是会有边,所以加上这些就好了. 比赛时的挫code----.. #include<cstdio> #include<math.…

Mishka and trip 题意: 有n个城市,第i个城市与第i+1个城市相连,他们边的权值等于i的美丽度*i+1的美丽度,有k个首都城市,一个首都城市与每个城市都相连,求所有边的权值. 题解: 先把n个城市存下来,之后开一个标记数组,来标记k个首都(这题这块很巧妙,正因为开了标记首都的数组,所以才把O(N^2)的算法降到了O(N)) 把所有城市的美丽值都加起来,遍历首都,每次遍历完就sum-首都,这样,最后求环的剩下的边就好了,环的剩下的边就是i不是首都,i+1也不是首都,那么就i*i+1…

B. Mishka and trip time limit per test 1 second memory limit per test 256 megabytes input  standard input output  standard output  Little Mishka is a great traveller and she visited many countries. After thinking about where to travel this time, she…

F - Mishka and trip Sample Output   Hint In the first sample test: In Peter's first test, there's only one cycle with 1 vertex. First player cannot make a move and loses. In his second test, there's one cycle with 1 vertex and one with 2. No one can…

B. Mishka and trip time limit per test:1 second memory limit per test:256 megabytes input:standard input output:standard output Little Mishka is a great traveller and she visited many countries. After thinking about where to travel this time, she cho…

题目链接: B. Mishka and trip time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Little Mishka is a great traveller and she visited many countries. After thinking about where to travel this time, s…

Description Little Mishka is a great traveller and she visited many countries. After thinking about where to travel this time, she chose XXX — beautiful, but little-known northern country. Here are some interesting facts about XXX: XXX consists of n …

time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output   Little Mishka is a great traveller and she visited many countries. After thinking about where to travel this time, she chose XXX — beautifu…

题意   Mishka想要去一个国家旅行,这个国家共有个城市,城市通过道路形成一个环,即第i个城市和第个城市之间有一条道路,此外城市和之间有一条道路.这个城市中有个首中心城市,中心城市与每个城市(除了自己)之间有一条道路.第城市个城市有一个魅力值,经过一条连接第个和第个城市的道路的费用是,求所有道路的费用之和是多少?   注意:任何两个城市之间最多只有一条路. 思路   先考虑所有中心城市:每条路只能算一遍,那么我们可以得到如下公式:   其中,代表所有城市的魅力值的和,代表已经计算过的中心城市…

题目:这里 题意:n个城市,每个城市有个魅力值vi,首先,有n条路将这n个城市连成一个环,1号城市连2号城市,2号连3号****n号连1号城市,每条路的魅力值是其连接的两个城市 的魅力值的乘积,这n个城市其中还有k个是特殊城市,每个特殊城市和任意一条城市都有一条路连接,看题目下面的图,保证每两个城市之间最多只有一条路,问所有路的 魅力值之和是多少? 首先是连接成环的路线魅力值,很好算,然后每个特殊城市的路线,先求出所有城市的魅力值之和sum,依次求特殊城市的时候用sum减去这个特殊城市本身以及两…