比較好的圖論
[cpp]
// BEGIN CUT HERE
// END CUT HERE
#line 5 "MonsterFarm.cpp"
#include <cstdlib>
#include <cctype>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <vector>
#include <string>
#include <iostream>
#include <sstream>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <fstream>
#include <numeric>
#include <iomanip>
#include <bitset>
#include <list>
#include <stdexcept>
#include <functional>
#include <utility>
#include <ctime>
using namespace std;
typedef long long ll;
class MonsterFarm
{
public:
int numMonsters(vector <string> transforms){
const int Mod=1000000007;
int g[51][51],d[51],path[51][51];
int len,i,j,k;
int n=transforms.size();
memset(g,0,sizeof(g));
memset(d,0,sizeof(d));
memset(path,0,sizeof(path));
for(i=0;i<n;i++){
len=transforms[i].size();
int tem=0;
for(j=0;j<len;j++){
if(transforms[i][j]==' '){
d[i]++;
g[i][tem-1]++;
path[i][tem-1]=1;
tem=0;
continue;
}
tem=tem*10+transforms[i][j]-'0';
}
d[i]++;
g[i][tem-1]++;
path[i][tem-1]=1;
}
for(k=0;k<n;k++)
for(i=0;i<n;i++)
for(j=0;j<n;j++)
path[i][j]=(path[i][j] || (path[i][k] && path[k][j]));
for(i=0;i<n;i++)
if(d[i]>=2 && path[0][i] && path[i][i])
return -1;
ll num[2][51];
int cur=0;
for(i=0;i<n;i++)
num[cur][i]=0;
num[cur][0]=1;
for(i=0;i<n;i++){
cur^=1;
for(j=0;j<n;j++)num[cur][j]=0;
for(j=0;j<n;j++)
for(k=0;k<n;k++)
num[cur][k]=(num[cur][k]+num[cur^1][j]*g[j][k])%Mod;
}
ll ans=0;
for(i=0;i<n;i++)
ans=(ans+num[cur][i])%Mod;
return (int)ans;
}
// BEGIN CUT HERE
public:
void run_test(int Case) { if ((Case == -1) || (Case == 0)) test_case_0(); if ((Case == -1) || (Case == 1)) test_case_1(); if ((Case == -1) || (Case == 2)) test_case_2(); if ((Case == -1) || (Case == 3)) test_case_3(); if ((Case == -1) || (Case == 4)) test_case_4(); if ((Case == -1) || (Case == 5)) test_case_5(); }
private:
template <typename T> string print_array(const vector<T> &V) { ostringstream os; os << "{ "; for (typename vector<T>::const_iterator iter = V.begin(); iter != V.end(); ++iter) os << '\"' << *iter << "\","; os << " }"; return os.str(); }
void verify_case(int Case, const int &Expected, const int &Received) { cerr << "Test Case #" << Case << "..."; if (Expected == Received) cerr << "PASSED" << endl; else { cerr << "FAILED" << endl; cerr << "\tExpected: \"" << Expected << '\"' << endl; cerr << "\tReceived: \"" << Received << '\"' << endl; } }
void test_case_0() { string Arr0[] = {"1"}; vector <string> Arg0(Arr0, Arr0 + (sizeof(Arr0) / sizeof(Arr0[0]))); int Arg1 = 1; verify_case(0, Arg1, numMonsters(Arg0)); }
void test_case_1() { string Arr0[] = {"1 1"}; vector <string> Arg0(Arr0, Arr0 + (sizeof(Arr0) / sizeof(Arr0[0]))); int Arg1 = -1; verify_case(1, Arg1, numMonsters(Arg0)); }
void test_case_2() { string Arr0[] = {"2", "3", "1"}; vector <string> Arg0(Arr0, Arr0 + (sizeof(Arr0) / sizeof(Arr0[0]))); int Arg1 = 1; verify_case(2, Arg1, numMonsters(Arg0)); }
void test_case_3() { string Arr0[] = {"1", "3 4", "2", "2"}; vector <string> Arg0(Arr0, Arr0 + (sizeof(Arr0) / sizeof(Arr0[0]))); int Arg1 = 1; verify_case(3, Arg1, numMonsters(Arg0)); }
void test_case_4() { string Arr0[] = {"2 2", "3", "4 4 4", "5", "6", "7 7 7 7", "7"}; vector <string> Arg0(Arr0, Arr0 + (sizeof(Arr0) / sizeof(Arr0[0]))); int Arg1 = 24; verify_case(4, Arg1, numMonsters(Arg0)); }
void test_case_5() { string Arr0[] = {"2 3","5 7","2 4","5","6","4","7"}; vector <string> Arg0(Arr0, Arr0 + (sizeof(Arr0) / sizeof(Arr0[0]))); int Arg1 = 5; verify_case(5, Arg1, numMonsters(Arg0)); }
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}; www.2cto.com
// BEGIN CUT HERE
int main()
{
MonsterFarm ___test;
___test.run_test(-1);
return 0;
}
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