test/atcoder/abc280_f.test.cpp

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• Last update: 2024-08-24 11:50:18+09:00
• Problem: https://atcoder.jp/contests/abc280/tasks/abc280_f

Depends on

• WeightedUnionFind (data-structure/weighted-union-find.hpp)
• template/alias.hpp
• template/debug.hpp
• template/func.hpp
• template/macro.hpp
• template/template.hpp
• template/util.hpp

Code

#define PROBLEM "https://atcoder.jp/contests/abc280/tasks/abc280_f"
#include "../../data-structure/weighted-union-find.hpp"
#include "../../template/template.hpp"

int main() {
    INT(N, M, Q);
    WeightedUnionFind<ll> uf(N);
    vector<bool> isinf(N, false);
    for (int i = 0; i < M; i++) {
        INT(a, b);
        a--, b--;
        LL(c);
        if (uf.issame(a, b) && uf.get_diff(a, b) != c) {
            isinf[a] = true;
        } else {
            uf.unite(a, b, c);
        }
    }
    for (auto v : uf.groups()) {
        bool flag = false;
        for (auto x : v) {
            if (isinf[x]) {
                flag = true;
                break;
            }
        }
        if (flag) {
            for (auto x : v) isinf[x] = true;
        }
    }
    for (int i = 0; i < Q; i++) {
        INT(a, b);
        a--, b--;
        if (!uf.issame(a, b)) {
            print("nan");
        }
        elif (isinf[a]) { print("inf"); }
        else {
            print(uf.get_diff(a, b));
        }
    }
}

#line 1 "test/atcoder/abc280_f.test.cpp"
#define PROBLEM "https://atcoder.jp/contests/abc280/tasks/abc280_f"
#line 2 "template/template.hpp"
#include <bits/stdc++.h>
#line 3 "template/macro.hpp"

#define overload3(_1, _2, _3, name, ...) name
#define all1(v) std::begin(v), std::end(v)
#define all2(v, a) std::begin(v), std::begin(v) + a
#define all3(v, a, b) std::begin(v) + a, std::begin(v) + b
#define all(...) overload3(__VA_ARGS__, all3, all2, all1)(__VA_ARGS__)
#define rall1(v) std::rbegin(v), std::rend(v)
#define rall2(v, a) std::rbegin(v), std::rbegin(v) + a
#define rall3(v, a, b) std::rbegin(v) + a, std::rbegin(v) + b
#define rall(...) overload3(__VA_ARGS__, rall3, rall2, rall1)(__VA_ARGS__)
#define elif else if
#define updiv(N, X) (((N) + (X) - 1) / (X))
#define sigma(a, b) (((a) + (b)) * ((b) - (a) + 1) / 2)
#define INT(...)     \
    int __VA_ARGS__; \
    scan(__VA_ARGS__)
#define LL(...)     \
    ll __VA_ARGS__; \
    scan(__VA_ARGS__)
#define STR(...)        \
    string __VA_ARGS__; \
    scan(__VA_ARGS__)
#define CHR(...)      \
    char __VA_ARGS__; \
    scan(__VA_ARGS__)
#define DOU(...)        \
    double __VA_ARGS__; \
    scan(__VA_ARGS__)
#define LD(...)     \
    ld __VA_ARGS__; \
    scan(__VA_ARGS__)
#define pb push_back
#define eb emplace_back
#line 3 "template/alias.hpp"

using ll = long long;
using ld = long double;
using pii = std::pair<int, int>;
using pll = std::pair<ll, ll>;
constexpr int inf = 1 << 30;
constexpr ll INF = 1LL << 60;
constexpr int dx[8] = {1, 0, -1, 0, 1, -1, 1, -1};
constexpr int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
constexpr int mod = 998244353;
constexpr int MOD = 1e9 + 7;
#line 3 "template/func.hpp"

template <typename T>
inline bool chmax(T& a, T b) { return ((a < b) ? (a = b, true) : (false)); }
template <typename T>
inline bool chmin(T& a, T b) { return ((a > b) ? (a = b, true) : (false)); }
template <typename T, typename U>
std::ostream &operator<<(std::ostream &os, const std::pair<T, U> &p) {
    os << p.first << " " << p.second;
    return os;
}
template <typename T, typename U>
std::istream &operator>>(std::istream &is, std::pair<T, U> &p) {
    is >> p.first >> p.second;
    return is;
}
template <typename T>
std::ostream &operator<<(std::ostream &os, const std::vector<T> &v) {
    for (auto it = std::begin(v); it != std::end(v);) {
        os << *it << ((++it) != std::end(v) ? " " : "");
    }
    return os;
}
template <typename T>
std::istream &operator>>(std::istream &is, std::vector<T> &v) {
    for (T &in : v) {
        is >> in;
    }
    return is;
}
inline void scan() {}
template <class Head, class... Tail>
inline void scan(Head &head, Tail &...tail) {
    std::cin >> head;
    scan(tail...);
}
template <class T>
inline void print(const T &t) { std::cout << t << '\n'; }
template <class Head, class... Tail>
inline void print(const Head &head, const Tail &...tail) {
    std::cout << head << ' ';
    print(tail...);
}
template <class... T>
inline void fin(const T &...a) {
    print(a...);
    exit(0);
}
#line 3 "template/util.hpp"

struct IOSetup {
    IOSetup() {
        std::cin.tie(nullptr);
        std::ios::sync_with_stdio(false);
        std::cout.tie(0);
        std::cout << std::fixed << std::setprecision(12);
        std::cerr << std::fixed << std::setprecision(12);
    }
} IOSetup;
#line 3 "template/debug.hpp"

#ifdef LOCAL
#include <dump.hpp>
#else
#define debug(...)
#endif
#line 8 "template/template.hpp"
using namespace std;
#line 3 "data-structure/weighted-union-find.hpp"

template <class T>
struct WeightedUnionFind {
    // core member
    vector<int> par;
    vector<T> weight;

    // constructor
    WeightedUnionFind() {}
    WeightedUnionFind(int N, T zero = 0) : par(N, -1), weight(N, zero) {}
    void init(int N, T zero = 0) {
        par.assign(N, -1);
        weight.assign(N, zero);
    }

    // core methods
    int root(int x) {
        if (par[x] < 0)
            return x;
        else {
            int r = root(par[x]);
            weight[x] += weight[par[x]];
            return par[x] = r;
        }
    }
    bool issame(int x, int y) { return root(x) == root(y); }

    // v[y] - v[x] = w
    bool unite(int x, int y, T w) {
        w += get_weight(x), w -= get_weight(y);
        x = root(x), y = root(y);
        if (x == y) return false;
        if (par[x] > par[y]) swap(x, y), w = -w;  // merge technique
        par[x] += par[y];
        par[y] = x;
        weight[y] = w;
        return true;
    }

    int size(int x) { return -par[root(x)]; }

    // get v[x]
    T get_weight(int x) {
        root(x);
        return weight[x];
    }

    // get v[y] - v[x]
    T get_diff(int x, int y) { return get_weight(y) - get_weight(x); }

    // get groups
    vector<vector<int>> groups() {
        vector<vector<int>> member(par.size());
        for (int v = 0; v < (int)par.size(); ++v) {
            member[root(v)].push_back(v);
        }
        vector<vector<int>> res;
        for (int v = 0; v < (int)par.size(); ++v) {
            if (!member[v].empty()) res.push_back(member[v]);
        }
        return res;
    }
};
#line 4 "test/atcoder/abc280_f.test.cpp"

int main() {
    INT(N, M, Q);
    WeightedUnionFind<ll> uf(N);
    vector<bool> isinf(N, false);
    for (int i = 0; i < M; i++) {
        INT(a, b);
        a--, b--;
        LL(c);
        if (uf.issame(a, b) && uf.get_diff(a, b) != c) {
            isinf[a] = true;
        } else {
            uf.unite(a, b, c);
        }
    }
    for (auto v : uf.groups()) {
        bool flag = false;
        for (auto x : v) {
            if (isinf[x]) {
                flag = true;
                break;
            }
        }
        if (flag) {
            for (auto x : v) isinf[x] = true;
        }
    }
    for (int i = 0; i < Q; i++) {
        INT(a, b);
        a--, b--;
        if (!uf.issame(a, b)) {
            print("nan");
        }
        elif (isinf[a]) { print("inf"); }
        else {
            print(uf.get_diff(a, b));
        }
    }
}

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