2017/finals/holes.cpp

// Hacker Cup 2017
// Final Round
// Fox Holes
// Jacob Plachta

#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); }

const int INF = (int)1e9;
const LD EPS = 1e-9;
const LD PI = acos(-1.0);

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);
}

#define MOD 1000000007
#define LIM 1100000

int L[LIM],A[LIM],B[LIM];
int sz,treeM[LIM],treeC[LIM],lazy[LIM];
set<int> SL,SR;

void Prop(int i)
{
	int v=lazy[i],j=i<<1,k=j+1;
	lazy[i]=0;
	treeM[i]+=v;
		if (i<sz)
			lazy[j]+=v,lazy[k]+=v;
}

void Update(int i,int r1,int r2,int a,int b,int v)
{
		if (a>b)
			return;
	Prop(i);
		if ((a<=r1) && (r2<=b))
		{
			lazy[i]+=v;
			return;
		}
	int m=(r1+r2)>>1,j=i<<1,k=j+1;
		if (a<=m)
			Update(j,r1,m,a,b,v);
		if (b>m)
			Update(k,m+1,r2,a,b,v);
	Prop(j),Prop(k);
	treeM[i]=min(treeM[j],treeM[k]);
	treeC[i]=0;
		if (treeM[i]==treeM[j])
			treeC[i]+=treeC[j];
		if (treeM[i]==treeM[k])
			treeC[i]+=treeC[k];
}

int Query(int i,int r1,int r2,int a,int b)
{
		if (a>b)
			return(0);
	Prop(i);
		if ((a<=r1) && (r2<=b))
			return(treeM[i] ? 0 : treeC[i]);
	int m=(r1+r2)>>1,j=i<<1,k=j+1,v=0;
		if (a<=m)
			v+=Query(j,r1,m,a,b);
		if (b>m)
			v+=Query(k,m+1,r2,a,b);
	return(v);
}

void Go(int i,int d)
{
	int a=A[i],b=B[i],p;
		if (a>b)
			swap(a,b);
	p=b-a;
		if (p%2)
		{
			// odd difference, key point must be outside [a, b-1]
			a/=2,b/=2;
			Update(1,0,sz-1,a,b-1,d);
			return;
		}
	// even difference, key point must be inside [a, b-1]
		if (d<0)
		{
			SL.erase(a);
			SR.erase(b-2);
		}
		else
		{
			SL.insert(a);
			SR.insert(b-2);
		}
}

int main()
{
	// vars
	int T,t;
	int N,M;
	int i,j,a,b;
	int ans;
	// testcase loop
	Read(T);
		Fox1(t,T)
		{
			// input, init pairs
			Read(N),Read(M);
			Fill(A,-1);
				Fox(i,N<<1)
				{
					Read(j),j--;
					L[i]=j;
						if (A[j]<0)
							A[j]=i;
						else
							B[j]=i;
				}
			// init data structures
				for(sz=1;sz<=N;sz<<=1);
			Fill(lazy,0);
			Fill(treeM,0);
				Fox(i,sz)
					treeC[sz+i]=1;
				FoxR1(i,sz-1)
					treeC[i]=treeC[i*2]+treeC[i*2+1];
			SL.clear(),SR.clear();
			// insert pairs
				Fox(i,N)
					Go(i,1);
			// process updates
			ans=0;
				while (M--)
				{
					// input
					Read(i),Read(j),i--,j--;
					a=L[i],b=L[j];
						if (a==b)
							goto Skip;
					// remove pairs
					Go(a,-1),Go(b,-1);
					// update pairs
					swap(L[i],L[j]);
						if (A[a]==i)
							A[a]=j;
						else
							B[a]=j;
						if (A[b]==j)
							A[b]=i;
						else
							B[b]=i;
					// re-insert pairs
					Go(a,1),Go(b,1);
Skip:;
					// compute current answer
						if (SL.empty())
							a=0,b=N*2;
						else
						{
							a=*SL.rbegin();
							b=*SR.begin();
						}
					a/=2;
					b/=2;
					ans=(ans+Query(1,0,sz-1,a,b))%MOD;
				}
			// output
			printf("Case #%d: %d\n",t,ans);
		}
	return(0);
}