ACdream1187-Rational Number Tree-模拟/找规律

找到规律模拟就可以了，用DFS模拟很简洁，用循环模拟比较直观（大概吧）

注意输入输出用%llu，1ULL<<64=0！被这几个小问题卡了好久

#include <cstdio>
#include <algorithm>
#include <cstring>

using namespace std;

int T;
unsigned long long n,p,q;
unsigned long long path;
int lev;

int main()
{
    scanf("%d",&T);
    for(int kase=1;kase<=T;kase++)
    {
        int op = 0;
        scanf("%d",&op);
        if(op == 1)
        {
            scanf("%llu",&n);
            lev=0;path=0;

            while((1ULL<<lev) <= n)
            {
                lev++;
                if(lev==64)break;
            }
            lev--;

            path = n - (1ULL<<lev);
            p=1;q=1;
            //printf("lev=%lld path=%lld
",lev,path);

            for(int i=lev-1;i>=0;i--)
            {
                if(path & (1ULL<<i)) p=p+q;
                else q = p+q;
            }
            printf("Case #%d: %llu %llu
",kase,p,q);
        }
        else if(op == 2)
        {
            scanf("%llu%llu",&p,&q);

            unsigned long long tp = p,tq = q;
            lev=0;path=0;
            while(true)
            {
                //printf("%llu %llu
",p,q);
                if(p==1ULL && q==1ULL) break;

                if(p > q) p -= q;
                else q -= p;
                lev++;
            }

            for(int i=0;i<lev;i++)
            {
                if(tp > tq)
                {
                    path += (1ULL<<i);
                    tp -= tq;
                }
                else
                    tq -= tp;
            }
            //printf("lev=%lld path=%lld
",lev,path);
            printf("Case #%d: %llu
",kase,path+(1ULL<<lev));
        }
    }
}