摘要： 【题目描述】You have been given a matrix CN x M, each element E of CN x M is positive and no more than 1000, The problem is that if there exist N numbers a1, a2,..., aN and M numbers b1, b2,..., bM, which satisfies that each elements in row-i multiplied with ai and each elements in column-j divided by bj, 阅读全文

摘要： 【题目描述】Given a permutation a1, a2,...aN of {1, 2,..., N}, we define its E-value as the amount of elements where ai > i. For example, the E-value of permutation {1, 3, 2, 4} is 1, while the E-value of {4, 3, 2, 1} is 2. You are requested to find how many permutations of {1, 2,..., N} whose E-value 阅读全文

摘要： 【题目描述】There are N cities, and M directed roads connecting them. Now you want to transport K units of goods from city 1 to city N. There are many robbers on the road, so you must be very careful. The more goods you carry, the more dangerous it is. To be more specific, for each road i, there is a coef 阅读全文