TC SRM 604 div2

第一次玩TC，感觉还不错，就是得熬夜不好。比赛前还做了点，练习下。

第一题，水题，秒杀 

第二题，上走或右走，其实就是3进制下是不是都是连续的1，可以用异或判断，只适用div2。

但正解是搜索，上下左右跑。

第三题，树DP，看了下，以为不会，把树的理解错了，没出。

涨rating 1333 好像直接进div1了。

第一题

#line 2 "FoxAndWord.cpp"
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <string>
#include <vector>
#define FOR(i,a,b) for(int i=a;i<=b;++i)
#define DWN(i,a,b) for(int i=a;i>=b;--i)
#define clr(f,z) memset(f,z,sizeof(f))
using namespace std;
class FoxAndWord 
{
	public:
	int howManyPairs(vector <string> words) 
	{
		int ans = 0;
		int len = words.size();
		FOR(i,0,len-1)
		FOR(j,i+1,len-1)
		if(OK(words[i],words[j]))
      ++ans;
    return ans;
	}
	bool OK(string a,string b)
	{
	  string c;
	  int len = a.size();
	  FOR(i,0,len-1)
	  {
	    c = "";
	    FOR(j,i,len-1)
	    c += a[j];
	    FOR(j,0,i-1)
	    c += a[j];
	    if(c == b)
        return 1;
	  }
	  return 0;
	}
};
// BEGIN CUT HERE
int main()
{
	
	return 0;
}
// END CUT HERE

第二题

#line 2 "FoxAndFencingEasy.cpp"
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <string>
#include <vector>
#define FOR(i,a,b) for(int i=a;i<=b;++i)
#define DWN(i,a,b) for(int i=a;i>=b;--i)
#define clr(f,z) memset(f,z,sizeof(f))
using namespace std;
class FoxAndFencingEasy
{
	public:
  int fabs(int x)
  {
    if(x<0)
      return -x;
    return x;
  }
	string WhoCanWin(int mov1, int mov2, int d)
	{
	  string s;
		if(mov1>=d)
      s="Ciel";
    else if(fabs(mov1-mov2)<=min(mov1,mov2))
    {
      s="Draw";
    }
    else if(mov1>mov2)
      s="Ciel";
    else s="Liss";

    return s;
	}
}ts;
// BEGIN CUT HERE
int main()
{
	int a,b,c;
	while(cin>>a>>b>>c)
  {
    cout<<ts.WhoCanWin(a,b,c)<<endl;
  }
	return 0;
}
// END CUT HERE

第三题

#line 2 "FoxConnection2.cpp"
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <string>
#include <vector>
#define FOR(i,a,b) for(int i=a;i<=b;++i)
#define DWN(i,a,b) for(int i=a;i>=b;--i)
#define clr(f,z) memset(f,z,sizeof(f))
#define LL long long
using namespace std;
const int MOD = 1e9+7;
const int mm = 255;
class Edge
{
public:
  int v,next;
};
class FoxConnection2
{
	public:
	  int N,M;
	  Edge e[mm+mm];
	  int head[mm],edge;
	  int dp[mm][mm];
	  bool vis[mm];
  void clear()
  {
    clr(head,-1); edge = 0;
  }
  void add(int u,int v)
  {
    e[edge].v = v; e[edge].next = head[u]; head[u] = edge++;
  }
  void dfs(int u)
  {
      vis[u] = 1;
      int v;
      dp[u][0] = dp[u][1] = 1;
      for(int l=head[u];~l;l=e[l].next)
      {
          v = e[l].v;
          if(vis[v])
            continue;

          dfs(v);
          DWN(i,M,2)
            FOR(j,1,i-1)
            {
             // cout<<u<<" uv "<<v<<"i="<<i<<" "<<dp[u][i]<<" "<<dp[u][i-j]<<" "<<dp[v][j]<<endl;
              dp[u][i] = (dp[u][i]+(LL)dp[u][i-j]*dp[v][j])%MOD;
            }
      }

    //  cout<<"u M "<<u<<" "<<dp[u][M]<<endl;
  }
	int ways(vector <int> A, vector <int> B, int k)
	{
      clear();

      N = A.size() + 1;
      M = k;

      FOR(i,0,A.size()-1)
      add(A[i],B[i]), add(B[i],A[i]);

      clr(dp,0); clr(vis,0);

      dfs(1);

      int ans = 0;
      FOR(i,1,N)
      {
        ans += dp[i][M];
        if(ans > MOD)
          ans -= MOD;
      }
    //  ans = dp[1][M];
      return ans;
	}
}solver;
// BEGIN CUT HERE
int main()
{
	while(1)
  {
    int a,b;
    vector<int> A,B;
    while(cin>>a>>b)
    {
      if(a == -1 && b == -1)
        break;
      A.push_back(a);
      B.push_back(b);
    }
    cin>>a;
    cout<<"ans = "<<solver.ways(A,B,a)<<endl;
  }
	return 0;
}
// END CUT HERE