#include<iostream> //#include<windows.h> #include<stdio.h> #include<algorithm> #include<cmath> #include<vector> #include<set> #include<map> #include<iomanip> #include<stack> #include<queue> #include<string> #include<cstring> #include<cstdlib> #include<ctime> #include<bitset> using namespace std; typedef vector<int> vi; typedef vector<vi> vvi; typedef pair<int, int> ii; typedef vector< ii > vii; typedef vector< pair < ii, int > > viii; typedef vector< vector < ii > > vvii; typedef pair < pair < int, int >, int > iii; typedef pair < pair < int, int >, pair < int, int > > iiii; typedef unsigned long long ull; typedef long long ll; typedef unsigned long long ull; typedef vector< ll > vll; typedef long double ld; typedef map < int, int > MAPA; #define boost ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0); #define sz(a) int((a).size()) #define pb push_back #define all(c) (c).begin(), (c).end() #define st first #define nd second #define rep(i,n) for(int i=0; i<(n); ++i) #define rall(c) (c).rbegin(), (c).rend() #define FOR(i, a, b) for (int (i)=(a); (i)<(b); (i)++) #define FOR2(i, a, b) for (int (i)=(a); (i)>=(b); (i)--) template<typename T> inline void setmin(T &x, T y) { if (y < x) x = y; } template<typename T> inline void setmax(T &x, T y) { if (y > x) x = y; } template<typename T> inline T gcd(T a, T b) { while (b)swap(a %= b, b); return a; } const int MAX = 2e6 + 7; const int T = 1 << 20; const int INF = 1e9 + 7; const ll BIG_INF = 1e18 + 5; ld e = 2.7182818284590452353602874713526624; ld PI = acos(-1); ld eps = 1e-19; ll n, m, k; const int MAXIK = 301; bitset<MAXIK> odw; int ile_wychodzi[MAXIK]; int ile_zmiana[MAXIK]; int wzorcowka[MAXIK]; int najd[MAXIK]; vector< pair < int , int > > pom; int wynik = INF; vvi DAG(MAXIK); vvi ODW(MAXIK); void wyrzuc(int x) { odw[x] = 1; for (auto u : ODW[x]) { ile_wychodzi[u]--; } } void przywroc(int x) { odw[x] = 0; for (auto u : ODW[x]) { ile_wychodzi[u]++; } } void policz_max_lenght() { int temp = 0; memset(ile_zmiana, 0, sizeof(ile_zmiana)); memset(najd, 0, sizeof(najd)); queue< pair< int, int> > Q; for (int i = 1; i <= n; i++) { if (!odw[i] && ile_wychodzi[i] == 0) { Q.push({ i , 0 }); } } while (Q.size()) { auto p = Q.front().st; auto d = Q.front().nd; Q.pop(); for (auto u : ODW[p]) { if (!odw[u]) { najd[u] = max(najd[u], d + 1); ile_zmiana[u]++; if (ile_wychodzi[u] - ile_zmiana[u] == 0) { Q.push({ u, najd[u] }); temp = max( temp, najd[u]); } } } } wynik = min(wynik, temp + 1); } void dfs1(int ile, int numer) { wyrzuc(numer); if (ile == k) { policz_max_lenght(); } else { for (int i = numer + 1; i <= n; i++) { dfs1(ile + 1, i); } } przywroc(numer); } void dfs2(int ile, int numer) { if( numer >= 0) { wyrzuc(pom[numer].nd); } if (ile == k) { policz_max_lenght(); } else { for (int i = numer + 1; i < 50; i++) { dfs2(ile + 1, i); } } if( numer >= 0 ){ przywroc( pom[numer].nd ); } } void herla(){ queue< pair< int, int> > Q; for (int i = 1; i <= n; i++) { if (sz(DAG[i])== 0) { Q.push({ i , 0 }); } } while (Q.size()) { auto p = Q.front().st; auto d = Q.front().nd; Q.pop(); for (auto u : ODW[p]) { najd[u] = max(najd[u], d + 1); ile_zmiana[u]++; if (sz(DAG[u]) - ile_zmiana[u] == 0) { Q.push({ u, najd[u] }); } } } for (int i = 1; i <= n; i++) { if (sz(ODW[i]) == 0) { pom.pb({ najd[i] , i }); Q.push({ i , najd[i] }); } } while (Q.size()) { auto p = Q.front().st; auto d = Q.front().nd; Q.pop(); for (auto u : DAG[p]) { najd[u] = max(najd[u], d); wzorcowka[u]++; if (sz(ODW[u]) - wzorcowka[u] == 0) { pom.push_back( { najd[u] , u }); Q.push({ u, najd[u] }); } } } sort( rall( pom ) ); pom.resize(50); dfs2(0,-1 ); } int main() { boost; cin >> n >> m >> k; if (k == n) { cout << 0; return 0; } for (int i = 0; i < m; i++) { int a, b; cin >> a >> b; ile_wychodzi[a]++; DAG[a].pb(b); ODW[b].pb(a); } if( (n <= 50 && k == 4 ) || ( n <= 70 && k == 3) || k <= 2 ){ dfs1(0, 0); cout << wynik ; } else{ // rob dla max 50 wierzcholkow na najdluzszych sciezkach herla(); cout << wynik; } }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 | #include<iostream> //#include<windows.h> #include<stdio.h> #include<algorithm> #include<cmath> #include<vector> #include<set> #include<map> #include<iomanip> #include<stack> #include<queue> #include<string> #include<cstring> #include<cstdlib> #include<ctime> #include<bitset> using namespace std; typedef vector<int> vi; typedef vector<vi> vvi; typedef pair<int, int> ii; typedef vector< ii > vii; typedef vector< pair < ii, int > > viii; typedef vector< vector < ii > > vvii; typedef pair < pair < int, int >, int > iii; typedef pair < pair < int, int >, pair < int, int > > iiii; typedef unsigned long long ull; typedef long long ll; typedef unsigned long long ull; typedef vector< ll > vll; typedef long double ld; typedef map < int, int > MAPA; #define boost ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0); #define sz(a) int((a).size()) #define pb push_back #define all(c) (c).begin(), (c).end() #define st first #define nd second #define rep(i,n) for(int i=0; i<(n); ++i) #define rall(c) (c).rbegin(), (c).rend() #define FOR(i, a, b) for (int (i)=(a); (i)<(b); (i)++) #define FOR2(i, a, b) for (int (i)=(a); (i)>=(b); (i)--) template<typename T> inline void setmin(T &x, T y) { if (y < x) x = y; } template<typename T> inline void setmax(T &x, T y) { if (y > x) x = y; } template<typename T> inline T gcd(T a, T b) { while (b)swap(a %= b, b); return a; } const int MAX = 2e6 + 7; const int T = 1 << 20; const int INF = 1e9 + 7; const ll BIG_INF = 1e18 + 5; ld e = 2.7182818284590452353602874713526624; ld PI = acos(-1); ld eps = 1e-19; ll n, m, k; const int MAXIK = 301; bitset<MAXIK> odw; int ile_wychodzi[MAXIK]; int ile_zmiana[MAXIK]; int wzorcowka[MAXIK]; int najd[MAXIK]; vector< pair < int , int > > pom; int wynik = INF; vvi DAG(MAXIK); vvi ODW(MAXIK); void wyrzuc(int x) { odw[x] = 1; for (auto u : ODW[x]) { ile_wychodzi[u]--; } } void przywroc(int x) { odw[x] = 0; for (auto u : ODW[x]) { ile_wychodzi[u]++; } } void policz_max_lenght() { int temp = 0; memset(ile_zmiana, 0, sizeof(ile_zmiana)); memset(najd, 0, sizeof(najd)); queue< pair< int, int> > Q; for (int i = 1; i <= n; i++) { if (!odw[i] && ile_wychodzi[i] == 0) { Q.push({ i , 0 }); } } while (Q.size()) { auto p = Q.front().st; auto d = Q.front().nd; Q.pop(); for (auto u : ODW[p]) { if (!odw[u]) { najd[u] = max(najd[u], d + 1); ile_zmiana[u]++; if (ile_wychodzi[u] - ile_zmiana[u] == 0) { Q.push({ u, najd[u] }); temp = max( temp, najd[u]); } } } } wynik = min(wynik, temp + 1); } void dfs1(int ile, int numer) { wyrzuc(numer); if (ile == k) { policz_max_lenght(); } else { for (int i = numer + 1; i <= n; i++) { dfs1(ile + 1, i); } } przywroc(numer); } void dfs2(int ile, int numer) { if( numer >= 0) { wyrzuc(pom[numer].nd); } if (ile == k) { policz_max_lenght(); } else { for (int i = numer + 1; i < 50; i++) { dfs2(ile + 1, i); } } if( numer >= 0 ){ przywroc( pom[numer].nd ); } } void herla(){ queue< pair< int, int> > Q; for (int i = 1; i <= n; i++) { if (sz(DAG[i])== 0) { Q.push({ i , 0 }); } } while (Q.size()) { auto p = Q.front().st; auto d = Q.front().nd; Q.pop(); for (auto u : ODW[p]) { najd[u] = max(najd[u], d + 1); ile_zmiana[u]++; if (sz(DAG[u]) - ile_zmiana[u] == 0) { Q.push({ u, najd[u] }); } } } for (int i = 1; i <= n; i++) { if (sz(ODW[i]) == 0) { pom.pb({ najd[i] , i }); Q.push({ i , najd[i] }); } } while (Q.size()) { auto p = Q.front().st; auto d = Q.front().nd; Q.pop(); for (auto u : DAG[p]) { najd[u] = max(najd[u], d); wzorcowka[u]++; if (sz(ODW[u]) - wzorcowka[u] == 0) { pom.push_back( { najd[u] , u }); Q.push({ u, najd[u] }); } } } sort( rall( pom ) ); pom.resize(50); dfs2(0,-1 ); } int main() { boost; cin >> n >> m >> k; if (k == n) { cout << 0; return 0; } for (int i = 0; i < m; i++) { int a, b; cin >> a >> b; ile_wychodzi[a]++; DAG[a].pb(b); ODW[b].pb(a); } if( (n <= 50 && k == 4 ) || ( n <= 70 && k == 3) || k <= 2 ){ dfs1(0, 0); cout << wynik ; } else{ // rob dla max 50 wierzcholkow na najdluzszych sciezkach herla(); cout << wynik; } } |