#include<bits/stdc++.h> using namespace std; using i64 = long long; using i32 = int; template<typename T> T load() { T x; cin >> x; return x; } template<typename T> vector<T> loadN(int s) { vector<T> vt(s); for(auto& el : vt) el = load<T>(); return vt; } template<typename T> ostream& operator<<(ostream& os, const vector<T>& vt) { for(auto& el : vt) os << el << ' '; return os; } struct Graph { Graph(i32 size):edges(size) {} void addEdge(i32 i, i32 j) { edges[i].push_back(j); } i32 size() const { return (i32) edges.size(); } vector<vector<i32>> edges; }; Graph loadGraph(i32 v, i32 e) { auto g = Graph(v); while(e --> 0) { auto f = load<i32>() - 1; auto t = load<i32>() - 1; g.addEdge(f, t); } return g; } i32 countScore(const Graph& g, vector<bool>& isBanned, vector<i32>& dyn) { auto score = -1; const i32 size = g.size(); for(i32 i = 0 ; i < size ; ++i) { if(isBanned[i]) continue; score = max(score, dyn[i]); for(auto& to : g.edges[i]) { if(isBanned[to]) continue; dyn[to] = max(dyn[to], dyn[i] + 1); } } fill(dyn.begin(), dyn.end(), 0); return score + 1; } template<typename T> void minEqual(T& x, const T& y) { x = min(x, y); } #define FOR(name, start) for(i32 name = start ; name < size ; ++name) i32 forOne(const Graph& g, vector<bool>& banned, vector<i32>& dyn) { const auto size = g.size(); auto score = size; FOR(i, 0) { banned[i] = true; minEqual(score, countScore(g, banned, dyn)); banned[i] = false; } return score; } i32 forTwo(const Graph& g, vector<bool>& banned, vector<i32>& dyn) { const auto size = g.size(); auto score = size; FOR(i, 0) { banned[i] = true; FOR(j, i + 1) { banned[j] = true; minEqual(score, countScore(g, banned, dyn)); banned[j] = false; } banned[i] = false; } return score; } i32 forThree(const Graph& g, vector<bool>& banned, vector<i32>& dyn) { const auto size = g.size(); auto score = size; FOR(i, 0) { banned[i] = true; FOR(j, i + 1) { banned[j] = true; FOR(k, j + 1) { banned[k] = true; minEqual(score, countScore(g, banned, dyn)); banned[k] = false; } banned[j] = false; } banned[i] = false; } return score; } i32 forFour(const Graph& g, vector<bool>& banned, vector<i32>& dyn) { const auto size = g.size(); auto score = size; FOR(i, 0) { banned[i] = true; FOR(j, i + 1) { banned[j] = true; FOR(k, j + 1) { banned[k] = true; FOR(l, k + 1) { banned[l] = true; minEqual(score, countScore(g, banned, dyn)); banned[l] = false; } banned[k] = false; } banned[j] = false; } banned[i] = false; } return score; } i32 main() { ios::sync_with_stdio(false); cin.tie(nullptr); auto graphSize = load<i32>(); auto edgeNum = load<i32>(); auto canErase = load<i32>(); auto g = loadGraph(graphSize, edgeNum); auto dyn = vector<i32>(graphSize); auto banned = vector<bool>(graphSize); auto solve = [&](i32 k) { if(k == 0) return countScore(g, banned, dyn); if(k == 1) return forOne(g, banned, dyn); if(k == 2) return forTwo(g, banned, dyn); if(k == 3) return forThree(g, banned, dyn); return forFour(g, banned, dyn); }; cout << solve(canErase) << '\n'; }
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 | #include<bits/stdc++.h> using namespace std; using i64 = long long; using i32 = int; template<typename T> T load() { T x; cin >> x; return x; } template<typename T> vector<T> loadN(int s) { vector<T> vt(s); for(auto& el : vt) el = load<T>(); return vt; } template<typename T> ostream& operator<<(ostream& os, const vector<T>& vt) { for(auto& el : vt) os << el << ' '; return os; } struct Graph { Graph(i32 size):edges(size) {} void addEdge(i32 i, i32 j) { edges[i].push_back(j); } i32 size() const { return (i32) edges.size(); } vector<vector<i32>> edges; }; Graph loadGraph(i32 v, i32 e) { auto g = Graph(v); while(e --> 0) { auto f = load<i32>() - 1; auto t = load<i32>() - 1; g.addEdge(f, t); } return g; } i32 countScore(const Graph& g, vector<bool>& isBanned, vector<i32>& dyn) { auto score = -1; const i32 size = g.size(); for(i32 i = 0 ; i < size ; ++i) { if(isBanned[i]) continue; score = max(score, dyn[i]); for(auto& to : g.edges[i]) { if(isBanned[to]) continue; dyn[to] = max(dyn[to], dyn[i] + 1); } } fill(dyn.begin(), dyn.end(), 0); return score + 1; } template<typename T> void minEqual(T& x, const T& y) { x = min(x, y); } #define FOR(name, start) for(i32 name = start ; name < size ; ++name) i32 forOne(const Graph& g, vector<bool>& banned, vector<i32>& dyn) { const auto size = g.size(); auto score = size; FOR(i, 0) { banned[i] = true; minEqual(score, countScore(g, banned, dyn)); banned[i] = false; } return score; } i32 forTwo(const Graph& g, vector<bool>& banned, vector<i32>& dyn) { const auto size = g.size(); auto score = size; FOR(i, 0) { banned[i] = true; FOR(j, i + 1) { banned[j] = true; minEqual(score, countScore(g, banned, dyn)); banned[j] = false; } banned[i] = false; } return score; } i32 forThree(const Graph& g, vector<bool>& banned, vector<i32>& dyn) { const auto size = g.size(); auto score = size; FOR(i, 0) { banned[i] = true; FOR(j, i + 1) { banned[j] = true; FOR(k, j + 1) { banned[k] = true; minEqual(score, countScore(g, banned, dyn)); banned[k] = false; } banned[j] = false; } banned[i] = false; } return score; } i32 forFour(const Graph& g, vector<bool>& banned, vector<i32>& dyn) { const auto size = g.size(); auto score = size; FOR(i, 0) { banned[i] = true; FOR(j, i + 1) { banned[j] = true; FOR(k, j + 1) { banned[k] = true; FOR(l, k + 1) { banned[l] = true; minEqual(score, countScore(g, banned, dyn)); banned[l] = false; } banned[k] = false; } banned[j] = false; } banned[i] = false; } return score; } i32 main() { ios::sync_with_stdio(false); cin.tie(nullptr); auto graphSize = load<i32>(); auto edgeNum = load<i32>(); auto canErase = load<i32>(); auto g = loadGraph(graphSize, edgeNum); auto dyn = vector<i32>(graphSize); auto banned = vector<bool>(graphSize); auto solve = [&](i32 k) { if(k == 0) return countScore(g, banned, dyn); if(k == 1) return forOne(g, banned, dyn); if(k == 2) return forTwo(g, banned, dyn); if(k == 3) return forThree(g, banned, dyn); return forFour(g, banned, dyn); }; cout << solve(canErase) << '\n'; } |