同学少年

摘要： DescriptionWe remind that the permutation of some final set is a one-to-one mapping of the set onto itself. Less formally, that is a way to reorder elements of the set. For example, one can define a permutation of the set {1,2,3,4,5} as follows: This record defines a permutation P as follows: P(1) = 阅读全文

摘要： 方法一：辗转相除法优点：代码简单，容易写。缺点：开销大，用时间多。代码：int gcd(int a,int b){ return b==0?a:gcd(b,a%b);}方法二：二进制算法优点：速度快。主要思想：前提：a>b，分情况讨论：1.a和b均为偶数，gcd(a,b)=2*gcd(a/2,b/2);2.a为偶数b为奇数，gcd(a,b)=gcd(a/2,b);3.a和b均为奇数,gcd(a,b)=gcd(a-b,b)代码：int gcd(int a,int b){ int t=1,c,d; while(a!=b) { if(a>=1; ... 阅读全文