摘要： 二分图匹配（匈牙利算法）1。一个二分图中的最大匹配数等于这个图中的最小点覆盖数König定理是一个二分图中很重要的定理，它的意思是，一个二分图中的最大匹配数等于这个图中的最小点覆盖数。如果你还不知道什么是最小点覆盖，我也在这里说一下：假如选了一个点就相当于覆盖了以它为端点的所有边，你需要选择最少的点来覆盖所有的边。2。最小路径覆盖=最小路径覆盖＝｜G｜－最大匹配数在一个N*N的有向图中，路径覆盖就是在图中找一些路经，使之覆盖了图中的所有顶点，且任何一个顶点有且只有一条路径与之关联；（如果把这些路径中的每条路径从它的起始点走到它的终点，那么恰好可以经过图中的每个顶点一次且仅一次）；如果 阅读全文

摘要： kiki's gameTime Limit: 5000/1000 MS (Java/Others)Memory Limit: 40000/1000 K (Java/Others)Total Submission(s): 3786Accepted Submission(s): 2193Problem DescriptionRecently kiki has nothing to do. While she is bored, an idea appears in his mind, she just playes the checkerboard game.The size of the 阅读全文

摘要： Good Luck in CET-4 Everybody!Time Limit: 1000/1000 MS (Java/Others)Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 2525Accepted Submission(s): 1585Problem Description大学英语四级考试就要来临了，你是不是在紧张的复习？也许紧张得连短学期的ACM都没工夫练习了，反正我知道的Kiki和Cici都是如此。当然，作为在考场浸润了十几载的当代大学生，Kiki和Cici更懂得考前的放松，所谓“张弛有道”就是这个意思。 阅读全文

摘要： 完数Time Limit: 2000/1000 MS (Java/Others)Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 11766Accepted Submission(s): 4082Problem Description完数的定义：如果一个大于1的正整数的所有因子之和等于它的本身，则称这个数是完数，比如6，28都是完数：6=1+2+3；28=1+2+4+7+14。本题的任务是判断两个正整数之间完数的个数。Input输入数据包含多行，第一行是一个正整数n，表示测试实例的个数，然后就是n个测试实例，每个实例占一 阅读全文

摘要： The time of a dayTime Limit: 2000/1000 MS (Java/Others)Memory Limit: 65768/65768 K (Java/Others)Total Submission(s): 742Accepted Submission(s): 327Problem DescriptionThere are no days and nights on byte island, so the residents here can hardly determine the length of a single day. Fortunately, they 阅读全文

摘要： Dwarven Sniper’s huntingTime Limit: 2000/1000 MS (Java/Others)Memory Limit: 65768/65768 K (Java/Others)Total Submission(s): 441Accepted Submission(s): 199Problem DescriptionNow the hunting starts in the world named DOTA, a stupid PC game which cannot play with others together.Among the individuals i 阅读全文

摘要： GameTime Limit: 2000/1000 MS (Java/Others)Memory Limit: 65768/65768 K (Java/Others)Total Submission(s): 638Accepted Submission(s): 210Problem DescriptionAlice and Bob are playing game with each other. They play the game on a 2D board. Alice has many vertical 1*2 tiles while Bob has many horizontal 2 阅读全文

摘要： BombingTime Limit: 4000/2000 MS (Java/Others)Memory Limit: 65768/65768 K (Java/Others)Total Submission(s): 1377Accepted Submission(s): 533Problem DescriptionIt’s a cruel war which killed millions of people and ruined series of cities. In order to stop it, let’s bomb the opponent’s base.It seems not 阅读全文

摘要： 24 PuzzleTime Limit: 2000/1000 MS (Java/Others)Memory Limit: 65768/65768 K (Java/Others)Total Submission(s): 1012Accepted Submission(s): 304Problem DescriptionDaniel likes to play a special board game, called 24 puzzle. 24 puzzle is such a game that there are tiles with the number 1 to 23 in a play 阅读全文

摘要： Color the ballTime Limit: 9000/3000 MS (Java/Others)Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 4258Accepted Submission(s): 2285Problem DescriptionN个气球排成一排，从左到右依次编号为1,2,3....N.每次给定2个整数a b(a <= b),lele便为骑上他的“小飞鸽"牌电动车从气球a开始到气球b依次给每个气球涂一次颜色。但是N次以后lele已经忘记了第I个气球已经涂过几次颜色了，你能帮他算出 阅读全文