graph/format.hpp

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• Last update: 2021-08-30 04:35:37+09:00
• Include: #include "graph/format.hpp"

Depends on

• utils/macros.hpp

Verified with

• graph/cartesian_tree.yukicoder-1031.test.cpp

Code

#pragma once
#include <cassert>
#include <utility>
#include <vector>
#include "../utils/macros.hpp"

std::pair<std::vector<std::vector<int> >, int> children_from_parent(const std::vector<int> & parent) {
    int n = parent.size();
    std::vector<std::vector<int> > children(n);
    int root = -1;
    REP (x, n) {
        if (parent[x] == -1) {
            assert (root == -1);
            root = x;
        } else {
            children[parent[x]].push_back(x);
        }
    }
    assert (root != -1);
    return std::make_pair(children, root);
}

std::vector<std::vector<int> > adjacent_list_from_children(const std::vector<std::vector<int> > & children) {
    int n = children.size();
    std::vector<std::vector<int> > g(n);
    REP (x, n) {
        for (int y : children[x]) {
            g[x].push_back(y);
            g[y].push_back(x);
        }
    }
    return g;
}

#line 2 "graph/format.hpp"
#include <cassert>
#include <utility>
#include <vector>
#line 2 "utils/macros.hpp"
#define REP(i, n) for (int i = 0; (i) < (int)(n); ++ (i))
#define REP3(i, m, n) for (int i = (m); (i) < (int)(n); ++ (i))
#define REP_R(i, n) for (int i = (int)(n) - 1; (i) >= 0; -- (i))
#define REP3R(i, m, n) for (int i = (int)(n) - 1; (i) >= (int)(m); -- (i))
#define ALL(x) std::begin(x), std::end(x)
#line 6 "graph/format.hpp"

std::pair<std::vector<std::vector<int> >, int> children_from_parent(const std::vector<int> & parent) {
    int n = parent.size();
    std::vector<std::vector<int> > children(n);
    int root = -1;
    REP (x, n) {
        if (parent[x] == -1) {
            assert (root == -1);
            root = x;
        } else {
            children[parent[x]].push_back(x);
        }
    }
    assert (root != -1);
    return std::make_pair(children, root);
}

std::vector<std::vector<int> > adjacent_list_from_children(const std::vector<std::vector<int> > & children) {
    int n = children.size();
    std::vector<std::vector<int> > g(n);
    REP (x, n) {
        for (int y : children[x]) {
            g[x].push_back(y);
            g[y].push_back(x);
        }
    }
    return g;
}

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