摘要： 今天比赛的时候做的一个题目。感觉这个题目不错。题目描述：DescriptionIn a laboratory, an assistant, Nathan Wada, is measuring weight differences between sample pieces pair by pair. He is using a balance because it can more precisely measure the weight difference between two samples than a spring scale when the samples have nearl 阅读全文

摘要： 这个题目初看上去是一个排列组合题，而实际上……也是一个排列组合题。题目描述是：DescriptionThe Stirling number of the second kind S(n, m) stands for the number of ways to partition a set of n things into m nonempty subsets. For example, there are seven ways to split a four-element set into two parts:{1, 2, 3} U {4}, {1, 2, 4} U {3}, {1, 3, 阅读全文

摘要： 今天做到的一个题目，题目的解法依据Lucas定理。题目描述：DescriptionFigure1showstheYangHuiTriangle.Wenumbertherowfromtoptobottom0,1,2,…andthecolumnfromlefttoright0,1,2,….IfusingC(n,k)representsthenumberofrown,columnk.TheYangHuiTrianglehasaregularpatternasfollows.C(n,0)=C(n,n)=1(n≥0)C(n,k)=C(n-1,k-1)+C(n-1,k)(0#include#include 阅读全文