DataStructure/test/aizu_dsl_1_b_dsu_weighted.test.cpp

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Last update: 2023-01-07 01:46:12+08:00
Problem: http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=DSL_1_B

Depends on

Code

#define PROBLEM "http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=DSL_1_B"

#include "../../template.h"
#include "../DSU/DSU_weighted.h"

void solve() {
    int n, q; cin >> n >> q;
    WeightedDSU<long long> dsu(n);
    while (q--) {
        int typ; cin >> typ;
        if (typ == 0) {
            int x, y, z; cin >> x >> y >> z;
            // f[y] = f[x] + z
            dsu.merge(x, y, z);
        } else {
            int x, y; cin >> x >> y;
            if (dsu.getRoot(x) == dsu.getRoot(y)) {
                cout << dsu.weight(y) - dsu.weight(x) << '\n';
            } else {
                cout << "?\n";
            }
        }
    }
}

#line 1 "DataStructure/test/aizu_dsl_1_b_dsu_weighted.test.cpp"
#define PROBLEM "http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=DSL_1_B"

#line 1 "template.h"
#include <bits/stdc++.h>
using namespace std;

#define FOR(i,a,b) for(int i=(a),_b=(b); i<=_b; i++)
#define FORD(i,a,b) for(int i=(a),_b=(b); i>=_b; i--)
#define REP(i,a) for(int i=0,_a=(a); i<_a; i++)
#define EACH(it,a) for(__typeof(a.begin()) it = a.begin(); it != a.end(); ++it)

#define DEBUG(x) { cout << #x << " = "; cout << (x) << endl; }
#define PR(a,n) { cout << #a << " = "; FOR(_,1,n) cout << a[_] << ' '; cout << endl; }
#define PR0(a,n) { cout << #a << " = "; REP(_,n) cout << a[_] << ' '; cout << endl; }

#define sqr(x) ((x) * (x))

// For printing pair, container, etc.
// Copied from https://quangloc99.github.io/2021/07/30/my-CP-debugging-template.html
template<class U, class V> ostream& operator << (ostream& out, const pair<U, V>& p) {
    return out << '(' << p.first << ", " << p.second << ')';
}

template<class Con, class = decltype(begin(declval<Con>()))>
typename enable_if<!is_same<Con, string>::value, ostream&>::type
operator << (ostream& out, const Con& con) {
    out << '{';
    for (auto beg = con.begin(), it = beg; it != con.end(); it++) {
        out << (it == beg ? "" : ", ") << *it;
    }
    return out << '}';
}
template<size_t i, class T> ostream& print_tuple_utils(ostream& out, const T& tup) {
    if constexpr(i == tuple_size<T>::value) return out << ")"; 
    else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); 
}
template<class ...U> ostream& operator << (ostream& out, const tuple<U...>& t) {
    return print_tuple_utils<0, tuple<U...>>(out, t);
}

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
long long get_rand(long long r) {
    return uniform_int_distribution<long long> (0, r-1)(rng);
}

template<typename T>
vector<T> read_vector(int n) {
    vector<T> res(n);
    for (int& x : res) cin >> x;
    return res;
}

void solve();

int main() {
    ios::sync_with_stdio(0); cin.tie(0);
    solve();
    return 0;
}
#line 1 "DataStructure/DSU/DSU_weighted.h"
template<class S>
struct WeightedDSU {
    std::vector<int> lab;
    std::vector<S> w;  // relative to parent

    WeightedDSU(int n) : lab(n, -1), w(n) {}

    int getRoot(int u) {
        if (lab[u] < 0) return u;
        return getRoot(lab[u]);
    }

    int weight(int u) {
        if (lab[u] < 0) return w[u];
        return w[u] + weight(lab[u]);
    }

    // weight(t) = weight(s) + diff
    // returns false if contradicts
    bool merge(int s, int t, S diff) {
        // jump to root
        diff = diff + weight(s) - weight(t);
        s = getRoot(s);
        t = getRoot(t);
        if (s == t) return diff == 0;
        if (lab[s] > lab[t]) {
            std::swap(s, t);
            diff = -diff;
        }
        lab[s] += lab[t];
        lab[t] = s;
        w[t] = diff;
        return true;
    }
};
#line 5 "DataStructure/test/aizu_dsl_1_b_dsu_weighted.test.cpp"

void solve() {
    int n, q; cin >> n >> q;
    WeightedDSU<long long> dsu(n);
    while (q--) {
        int typ; cin >> typ;
        if (typ == 0) {
            int x, y, z; cin >> x >> y >> z;
            // f[y] = f[x] + z
            dsu.merge(x, y, z);
        } else {
            int x, y; cin >> x >> y;
            if (dsu.getRoot(x) == dsu.getRoot(y)) {
                cout << dsu.weight(y) - dsu.weight(x) << '\n';
            } else {
                cout << "?\n";
            }
        }
    }
}