2018/finals/stockholm.cpp

// Stockholm
// Solution by Jacob Plachta

#define DEBUG 0

#include <algorithm>
#include <functional>
#include <numeric>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <complex>
#include <cstdlib>
#include <ctime>
#include <cstring>
#include <cassert>
#include <string>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <sstream>
using namespace std;

#define LL long long
#define LD long double
#define PR pair<int,int>

#define Fox(i,n) for (i=0; i<n; i++)
#define Fox1(i,n) for (i=1; i<=n; i++)
#define FoxI(i,a,b) for (i=a; i<=b; i++)
#define FoxR(i,n) for (i=(n)-1; i>=0; i--)
#define FoxR1(i,n) for (i=n; i>0; i--)
#define FoxRI(i,a,b) for (i=b; i>=a; i--)
#define Foxen(i,s) for (i=s.begin(); i!=s.end(); i++)
#define Min(a,b) a=min(a,b)
#define Max(a,b) a=max(a,b)
#define Sz(s) int((s).size())
#define All(s) (s).begin(),(s).end()
#define Fill(s,v) memset(s,v,sizeof(s))
#define pb push_back
#define mp make_pair
#define x first
#define y second

template<typename T> T Abs(T x) { return(x<0 ? -x : x); }
template<typename T> T Sqr(T x) { return(x*x); }
string plural(string s) { return(Sz(s) && s[Sz(s)-1]=='x' ? s+"en" : s+"s"); }

const int INF = (int)1e9;
const LD EPS = 1e-12;
const LD PI = acos(-1.0);

#if DEBUG
#define GETCHAR getchar
#else
#define GETCHAR getchar_unlocked
#endif

bool Read(int &x)
{
	char c,r=0,n=0;
	x=0;
		for(;;)
		{
			c=GETCHAR();
				if ((c<0) && (!r))
					return(0);
				if ((c=='-') && (!r))
					n=1;
				else
				if ((c>='0') && (c<='9'))
					x=x*10+c-'0',r=1;
				else
				if (r)
					break;
		}
		if (n)
			x=-x;
	return(1);
}

pair<int,bool> Cost(string s)
{
		if (!Sz(s))
			return(mp(0,0));
	int i=Sz(s)-1;
	// delete equal digits from the end
		while ((i) && (s[i]==s[i-1]))
			i--;
	// delete one more digit from the end
		if (i)
			i--;
	// now empty?
		if (!i)
			return(mp(0,Sz(s)>=2 && s[0]==s[Sz(s)-1]));
	pair<int,bool> c=Cost(s.substr(0,i));
	c.x++;
	return(c);
}

int main()
{
		if (DEBUG)
			freopen("in.txt","r",stdin);
	// vars
	int T,t;
	LL A,B;
	string X,Y;
	int p,ans;
	pair<int,bool> c1,c2;
	// testcase loop
	Read(T);
		Fox1(t,T)
		{
			// input
			scanf("%lld%lld",&A,&B);
			// convert nodes to binary
			A++,B++;
			X=Y="";
				while (A)
					X=char(A%2+'0')+X,A/=2;
				while (B)
					Y=char(B%2+'0')+Y,B/=2;
			// find LCA
				Fox(p,min(Sz(X),Sz(Y)))
					if (X[p]!=Y[p])
						break;
			// compute costs to LCA
			X=X.substr(p);
			Y=Y.substr(p);
			c1=Cost(X),c2=Cost(Y);
			ans=c1.x+c2.x;
			// at least one node is coming from the outside, and neither is the LCA?
				if ((Sz(X)) && (Sz(Y)) && (c1.y || c2.y))
					ans++;
			// output
			printf("Case #%d: %d\n",t,ans);
		}
	return(0);
}