#include <iostream> #include <list> #include <vector> #include <unordered_map> #include <queue> using namespace std; struct city; struct connection { city& to; long long cost; connection(city& to, long long cost) : to(to), cost(cost) {} }; struct city { int id; long long income = 0; long long currentCost = -1; vector<connection> connections; city(int id, long long income) : id(id), income(income) {} long long NetIncome() { return income - currentCost; } }; bool NewIsBetter(city* oldCity, city& newCity) { if (oldCity == nullptr) return true; if (oldCity->NetIncome() < newCity.NetIncome()) return true; if (oldCity->NetIncome() > newCity.NetIncome()) return false; return newCity.id < oldCity->id; } city* CalculateBest(city* currentCity) { city* bestCity = nullptr; queue<city*> cities; cities.push(currentCity); currentCity->currentCost = 0; while (cities.empty() == false) { currentCity = cities.front(); cities.pop(); //search through tree for (auto& connection : currentCity->connections) { auto& city = connection.to; if (city.currentCost != -1)//visited continue; cities.push(&city); city.currentCost = currentCity->currentCost + connection.cost; if (NewIsBetter(bestCity, city)) bestCity = &city; } } return bestCity; } int main() { int n, q; cin >> n; cin >> q; vector<city> cities; unordered_map<int, unordered_map<int, connection*>> connectionsmap; vector<int> output; for (int i = 1; i <= n; i++) { long long income; cin >> income; cities.push_back({ i, income }); } for (int i = 1; i < n; i++) { int from, to; long long cost; cin >> from; cin >> to; cin >> cost; from--; to--; cities[from].connections.push_back({ cities[to], cost }); cities[to].connections.push_back({ cities[from], cost }); } for (auto& city : cities) { for (auto& connection : city.connections) { connectionsmap[city.id][connection.to.id] = &connection; } } auto currentCity = &(cities.front()); for (int i = 0; i < q; i++) { int type; cin >> type; switch (type) { case 1: int city; cin >> city; cin >> cities[city - 1].income; break; default: int from, to; long long cost; cin >> from; cin >> to; cin >> cost; connectionsmap[from][to]->cost = cost; connectionsmap[to][from]->cost = cost; break; } for (auto& city : cities) city.currentCost = -1; currentCity = CalculateBest(currentCity); output.push_back(currentCity->id); } for (auto& id : output) cout << id << " "; return 0; }
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 | #include <iostream> #include <list> #include <vector> #include <unordered_map> #include <queue> using namespace std; struct city; struct connection { city& to; long long cost; connection(city& to, long long cost) : to(to), cost(cost) {} }; struct city { int id; long long income = 0; long long currentCost = -1; vector<connection> connections; city(int id, long long income) : id(id), income(income) {} long long NetIncome() { return income - currentCost; } }; bool NewIsBetter(city* oldCity, city& newCity) { if (oldCity == nullptr) return true; if (oldCity->NetIncome() < newCity.NetIncome()) return true; if (oldCity->NetIncome() > newCity.NetIncome()) return false; return newCity.id < oldCity->id; } city* CalculateBest(city* currentCity) { city* bestCity = nullptr; queue<city*> cities; cities.push(currentCity); currentCity->currentCost = 0; while (cities.empty() == false) { currentCity = cities.front(); cities.pop(); //search through tree for (auto& connection : currentCity->connections) { auto& city = connection.to; if (city.currentCost != -1)//visited continue; cities.push(&city); city.currentCost = currentCity->currentCost + connection.cost; if (NewIsBetter(bestCity, city)) bestCity = &city; } } return bestCity; } int main() { int n, q; cin >> n; cin >> q; vector<city> cities; unordered_map<int, unordered_map<int, connection*>> connectionsmap; vector<int> output; for (int i = 1; i <= n; i++) { long long income; cin >> income; cities.push_back({ i, income }); } for (int i = 1; i < n; i++) { int from, to; long long cost; cin >> from; cin >> to; cin >> cost; from--; to--; cities[from].connections.push_back({ cities[to], cost }); cities[to].connections.push_back({ cities[from], cost }); } for (auto& city : cities) { for (auto& connection : city.connections) { connectionsmap[city.id][connection.to.id] = &connection; } } auto currentCity = &(cities.front()); for (int i = 0; i < q; i++) { int type; cin >> type; switch (type) { case 1: int city; cin >> city; cin >> cities[city - 1].income; break; default: int from, to; long long cost; cin >> from; cin >> to; cin >> cost; connectionsmap[from][to]->cost = cost; connectionsmap[to][from]->cost = cost; break; } for (auto& city : cities) city.currentCost = -1; currentCity = CalculateBest(currentCity); output.push_back(currentCity->id); } for (auto& id : output) cout << id << " "; return 0; } |