A .Banana Bananas are the favoured food of monkeys. In the forest, there is a Banana Company that provides bananas from different places. The company has two lists. The first list records the types of bananas preferred by different monkeys, and the s…

题目 https://nanti.jisuanke.com/t/16958 题意 给定一个n(n<=500)个点的无向图,给每条边黑白染色,输出同色三角形最少的个数和对应的方案 分析 首先考虑给定一个染色完毕的无向图,如何求同色三角形的个数 同色三角形的个数=总的个数-异色三角形的个数 而一个异色三角形对应两个异色角,所以我们可以通过算异色角的个数来计算异色三角形的个数 而异色角是有一个固定的点i引出去的n-1条边所决定的 设某个点i有$x_i$条1边,有$n-1-x_i$条2边 可以发现异色角…

题目连接 : https://nanti.jisuanke.com/t/A1256 Life is a journey, and the road we travel has twists and turns, which sometimes lead us to unexpected places and unexpected people. Now our journey of Dalian ends. To be carefully considered are the following…

Life is a journey, and the road we travel has twists and turns, which sometimes lead us to unexpected places and unexpected people. Now our journey of Dalian ends. To be carefully considered are the following questions. Next month in Xian, an essenti…

题目链接 题意 : 给出一副图,大连是起点,终点是西安,要求你求出从起点到终点且经过中转点上海的最小花费是多少? 分析 : 最短路是最小费用最大流的一个特例,所以有些包含中转限制或者经过点次数有限制的最短路问题都可以考虑使用最小费用最大流来建图解决. 首先对于每个点都只能经过一次这个限制,在网络流中是比较常见的一个限制,只要将所有的点由一拆二且两点间连容量为 1 且花费为 0 的边. 这题的建图很巧妙,是将中转点作为汇点,提示到了这里不如停下来想想如何建图? 然后抽象出一个超级源点,然后将起点和…

transaction transaction transaction Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 132768/132768 K (Java/Others)Total Submission(s): 1077    Accepted Submission(s): 521 Problem Description Kelukin is a businessman. Every day, he travels arou…

card card card Time Limit: 8000/4000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1230    Accepted Submission(s): 549 Problem Description As a fan of Doudizhu, WYJ likes collecting playing cards very much. One day…

题目描述 Two out-of-control cars crashed within about a half-hour Wednesday afternoon on Deer Park Avenue. This accident alarmed the district government.It jumpstarted a vibrant new technology to predict potential car accidents.Engineers depicted a movin…

Banana Bananas are the favoured food of monkeys. In the forest, there is a Banana Company that provides bananas from different places. The company has two lists. The first list records the types of bananas preferred by different monkeys, and the seco…

2017 ACM-ICPC 亚洲区(乌鲁木齐赛区)网络赛  H Skiing In this winter holiday, Bob has a plan for skiing at the mountain resort. This ski resort has MM different ski paths and NN different flags situated at those turning points. The ii-th path from the S_iS​i​​-th f…