14.约瑟夫环问题

http://zhedahht.blog.163.com/blog/static/2541117420072250322938/

http://en.wikipedia.org/wiki/Josephus_problem

证明略。

//f(1,m)=0

//f(n,m)=[f(n-1,m)+m]%n (n>=2)

int LastRemaining_Solution2(int n, unsigned int m)

{

    // invalid input

    if(n <= 0 || m < 0)

        return -1;

// if there are only one integer in the circle initially,

    // of course the last remaining one is 0

    int lastinteger = 0;
// find the last remaining one in the circle with n integers

    for (int i = 2; i <= n; i ++)

        lastinteger = (lastinteger + m) % i;
return lastinteger;

}

14.约瑟夫环问题