KRisen

摘要： Can you solve this equation?Time Limit: 2000/1000 MS (Java/Others)Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 4276Accepted Submission(s): 1989Problem DescriptionNow,given the equation 8*x^4 + 7*x^3 + 2*x^2 + 3*x + 6 == Y,can you find its solution between 0 and 100;Now please try yo 阅读全文

摘要： 原文地址：http://hunteagle.iteye.com/blog/118551计算理论中，没有Hash函数的说法，只有单向函数的说法。所谓的单向函数，是一个复杂的定义，大家可以去看计算理论或者密码学方面的数据。用“人类”的语言描述单向函数就是：如果某个函数在给定输入的时候，很容易计算出其结果来；而当给定结果的时候，很难计算出输入来，这就是单项函数。各种加密函数都可以被认为是单向函数的逼近。Hash函数（或者成为散列函数）也可以看成是单向函数的一个逼近。即它接近于满足单向函数的定义。Hash函数还有另外的含义。实际中的Hash函数是指把一个大范围映射到一个小范围。把大范围映射到一个小范围 阅读全文

摘要： BabelfishTime Limit:3000MSMemory Limit:65536KTotal Submissions:26333Accepted:11301DescriptionYou have just moved from Waterloo to a big city. The people here speak an incomprehensible dialect of a foreign language. Fortunately, you have a dictionary to he... 阅读全文

摘要： 4 Values whose Sum is 0Time Limit:15000MSMemory Limit:228000KTotal Submissions:12224Accepted:3426Case Time Limit:5000MSDescriptionThe SUM problem can be formulated as follows: given four lists A, B, C, D of integer values, compute how many quadruplet (a, b, c, d ) ∈ A x B x C x D are such that a + b 阅读全文