This documentation is automatically generated by online-judge-tools/verification-helper
#include "graph/utility.hpp"
グラフを取り扱う便利関数詰め合わせ。
$g$ から孤立点を取り除いたグラフを返す。
グラフを隣接行列表現で与え、 $g$ から孤立店を取り除いたグラフを返す。
#pragma once
#include "../graph/base.hpp"
namespace ebi {
template <class T> Graph<T> remove_isolated_vertex(const Graph<T> &g) {
const int n = g.node_number();
std::vector<int> seen(n, -1);
for (auto e : g.get_edges()) {
seen[e.from] = seen[e.to] = 1;
}
int sz = 0;
for (int i = 0; i < n; i++) {
if (seen[i] != -1) seen[i] = sz++;
}
Graph<T> gh(sz);
for (auto e : g.get_edges()) {
gh.add_undirected_edge(seen[e.from], seen[e.to], e.cost);
}
gh.build();
return gh;
}
template <class T>
std::vector<std::vector<T>> remove_isolated_vertex(
const std::vector<std::vector<T>> &g) {
const int n = (int)g.size();
std::vector<int> seen(n, -1);
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
if (g[i][j] != 0) seen[i] = seen[j] = 1;
}
}
int sz = 0;
for (int i = 0; i < n; i++) {
if (seen[i] != -1) seen[i] = sz++;
}
std::vector gh(sz, std::vector<int>(sz, 0));
for (int i = 0; i < n; i++) {
if (seen[i] == -1) continue;
for (int j = 0; j < n; j++) {
if (seen[j] == -1) continue;
gh[seen[i]][seen[j]] += g[i][j];
}
}
return gh;
}
} // namespace ebi
#line 2 "graph/utility.hpp"
#line 2 "graph/base.hpp"
#include <cassert>
#include <iostream>
#include <ranges>
#include <vector>
#line 2 "data_structure/simple_csr.hpp"
#line 4 "data_structure/simple_csr.hpp"
#include <utility>
#line 6 "data_structure/simple_csr.hpp"
namespace ebi {
template <class E> struct simple_csr {
simple_csr() = default;
simple_csr(int n, const std::vector<std::pair<int, E>>& elements)
: start(n + 1, 0), elist(elements.size()) {
for (auto e : elements) {
start[e.first + 1]++;
}
for (auto i : std::views::iota(0, n)) {
start[i + 1] += start[i];
}
auto counter = start;
for (auto [i, e] : elements) {
elist[counter[i]++] = e;
}
}
simple_csr(const std::vector<std::vector<E>>& es)
: start(es.size() + 1, 0) {
int n = es.size();
for (auto i : std::views::iota(0, n)) {
start[i + 1] = (int)es[i].size() + start[i];
}
elist.resize(start.back());
for (auto i : std::views::iota(0, n)) {
std::copy(es[i].begin(), es[i].end(), elist.begin() + start[i]);
}
}
int size() const {
return (int)start.size() - 1;
}
const auto operator[](int i) const {
return std::ranges::subrange(elist.begin() + start[i],
elist.begin() + start[i + 1]);
}
auto operator[](int i) {
return std::ranges::subrange(elist.begin() + start[i],
elist.begin() + start[i + 1]);
}
const auto operator()(int i, int l, int r) const {
return std::ranges::subrange(elist.begin() + start[i] + l,
elist.begin() + start[i + 1] + r);
}
auto operator()(int i, int l, int r) {
return std::ranges::subrange(elist.begin() + start[i] + l,
elist.begin() + start[i + 1] + r);
}
private:
std::vector<int> start;
std::vector<E> elist;
};
} // namespace ebi
#line 9 "graph/base.hpp"
namespace ebi {
template <class T> struct Edge {
int from, to;
T cost;
int id;
};
template <class E> struct Graph {
using cost_type = E;
using edge_type = Edge<cost_type>;
Graph(int n_) : n(n_) {}
Graph() = default;
void add_edge(int u, int v, cost_type c) {
buff.emplace_back(u, edge_type{u, v, c, m});
edges.emplace_back(edge_type{u, v, c, m++});
}
void add_undirected_edge(int u, int v, cost_type c) {
buff.emplace_back(u, edge_type{u, v, c, m});
buff.emplace_back(v, edge_type{v, u, c, m});
edges.emplace_back(edge_type{u, v, c, m});
m++;
}
void read_tree(int offset = 1, bool is_weighted = false) {
read_graph(n - 1, offset, false, is_weighted);
}
void read_parents(int offset = 1) {
for (auto i : std::views::iota(1, n)) {
int p;
std::cin >> p;
p -= offset;
add_undirected_edge(p, i, 1);
}
build();
}
void read_graph(int e, int offset = 1, bool is_directed = false,
bool is_weighted = false) {
for (int i = 0; i < e; i++) {
int u, v;
std::cin >> u >> v;
u -= offset;
v -= offset;
if (is_weighted) {
cost_type c;
std::cin >> c;
if (is_directed) {
add_edge(u, v, c);
} else {
add_undirected_edge(u, v, c);
}
} else {
if (is_directed) {
add_edge(u, v, 1);
} else {
add_undirected_edge(u, v, 1);
}
}
}
build();
}
void build() {
assert(!prepared);
csr = simple_csr<edge_type>(n, buff);
buff.clear();
prepared = true;
}
int size() const {
return n;
}
int node_number() const {
return n;
}
int edge_number() const {
return m;
}
edge_type get_edge(int i) const {
return edges[i];
}
std::vector<edge_type> get_edges() const {
return edges;
}
const auto operator[](int i) const {
return csr[i];
}
auto operator[](int i) {
return csr[i];
}
private:
int n, m = 0;
std::vector<std::pair<int,edge_type>> buff;
std::vector<edge_type> edges;
simple_csr<edge_type> csr;
bool prepared = false;
};
} // namespace ebi
#line 4 "graph/utility.hpp"
namespace ebi {
template <class T> Graph<T> remove_isolated_vertex(const Graph<T> &g) {
const int n = g.node_number();
std::vector<int> seen(n, -1);
for (auto e : g.get_edges()) {
seen[e.from] = seen[e.to] = 1;
}
int sz = 0;
for (int i = 0; i < n; i++) {
if (seen[i] != -1) seen[i] = sz++;
}
Graph<T> gh(sz);
for (auto e : g.get_edges()) {
gh.add_undirected_edge(seen[e.from], seen[e.to], e.cost);
}
gh.build();
return gh;
}
template <class T>
std::vector<std::vector<T>> remove_isolated_vertex(
const std::vector<std::vector<T>> &g) {
const int n = (int)g.size();
std::vector<int> seen(n, -1);
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
if (g[i][j] != 0) seen[i] = seen[j] = 1;
}
}
int sz = 0;
for (int i = 0; i < n; i++) {
if (seen[i] != -1) seen[i] = sz++;
}
std::vector gh(sz, std::vector<int>(sz, 0));
for (int i = 0; i < n; i++) {
if (seen[i] == -1) continue;
for (int j = 0; j < n; j++) {
if (seen[j] == -1) continue;
gh[seen[i]][seen[j]] += g[i][j];
}
}
return gh;
}
} // namespace ebi