This documentation is automatically generated by online-judge-tools/verification-helper
#define PROBLEM "https://onlinejudge.u-aizu.ac.jp/courses/library/3/DSL/1/DSL_1_B"
#include "../Library/Template.hpp"
#include "../Library/DataStructure/WeightedUnionFind.hpp"
int main(){
cin.tie(0)->sync_with_stdio(false);
int n, q; cin >> n >> q;
WeightedUnionFind<ll> uf(n);
while(q--){
int query; cin >> query;
if(query == 0){
int x, y, z; cin >> x >> y >> z;
uf.Unite(x, y, z);
}
else{
int x, y; cin >> x >> y;
if(!uf.Same(x, y)) cout << "?" << '\n';
else cout << uf.Diff(x, y) << '\n';
}
}
}#line 1 "verify/AOJ-DSL-1-B.test.cpp"
#define PROBLEM "https://onlinejudge.u-aizu.ac.jp/courses/library/3/DSL/1/DSL_1_B"
#line 2 "Library/Template.hpp"
#line 2 "Library/Common.hpp"
/**
* @file Common.hpp
*/
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cstdint>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <utility>
#include <vector>
using namespace std;
using ll = int64_t;
using ull = uint64_t;
constexpr const ll INF = (1LL << 62) - (3LL << 30) - 1;
#line 4 "Library/Template.hpp"
inline bool YnPrint(bool flag){cout << (flag ? "Yes" : "No") << '\n'; return flag;}
inline bool YNPrint(bool flag){cout << (flag ? "YES" : "NO") << '\n'; return flag;}
template<typename Container>
inline void Sort(Container &container){sort(container.begin(), container.end());}
template<typename Container>
inline void ReverseSort(Container &container){sort(container.rbegin(), container.rend());}
template<typename Container>
inline void Reverse(Container &container){reverse(container.begin(), container.end());}
template<typename Value>
inline int PopCount(const Value &value){return __builtin_popcount(value);}
template<typename Value>
inline Value Floor(Value numerator, Value denominator){if(denominator < 0) numerator *= -1, denominator *= -1; return numerator < 0 ? (numerator + 1) / denominator - 1 : numerator / denominator;}
template<typename Value>
inline Value Ceil(Value numerator, Value denominator){if(denominator < 0) numerator *= -1, denominator *= -1; return numerator > 0 ? (numerator - 1) / denominator + 1 : numerator / denominator;}
template<typename Value>
inline int LowerBoundIndex(const vector<Value> &container, const Value &value){return distance(container.begin(), lower_bound(container.begin(), container.end(), value));}
template<typename Value>
inline int UpperBoundIndex(const vector<Value> &container, const Value &value){return distance(container.begin(), upper_bound(container.begin(), container.end(), value));}
template<typename Value>
inline bool Between(const Value &lower, const Value &x, const Value &higher){return lower <= x && x <= higher;}
template<typename Value>
inline bool InGrid(const Value &y, const Value &x, const Value &ymax, const Value &xmax){return Between(0, y, ymax - 1) && Between(0, x, xmax - 1);}
template<typename Value>
inline Value Median(const Value &a, const Value &b, const Value &c){return Between(b, a, c) || Between(c, a, b) ? a : (Between(a, b, c) || Between(c, b, a) ? b : c);}
template<typename Value>
inline Value Except(Value &src, Value &cond, Value &excp){return (src == cond ? excp : src);}
template<class Value>
bool chmin(Value &src, const Value &cmp){if(src > cmp){src = cmp; return true;} return false;}
template<class Value>
bool chmax(Value &src, const Value &cmp){if(src < cmp){src = cmp; return true;} return false;}
template<typename Value>
inline Value min(vector<Value> &v){return *min_element((v).begin(), (v).end());}
template<typename Value>
inline Value max(vector<Value> &v){return *max_element((v).begin(), (v).end());}
const int dx4[4] = {1, 0, -1, 0};
const int dy4[4] = {0, -1, 0, 1};
const int dx8[8] = {1, 1, 0, -1, -1, -1, 0, 1};
const int dy8[8] = {0, -1, -1, -1, 0, 1, 1, 1};
vector<pair<int, int>> adjacent(int current_y, int current_x, int max_y, int max_x, bool dir_8 = false){
vector<pair<int, int>> ret;
for(int d = 0; d < 4 * (1 + dir_8); ++d){
int next_y = current_y + (dir_8 ? dy8[d] : dy4[d]);
int next_x = current_x + (dir_8 ? dx8[d] : dx4[d]);
if(InGrid(next_y, next_x, max_y, max_x)){
ret.emplace_back(next_y, next_x);
}
}
return ret;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p){
os << p.first << " " << p.second;
return os;
}
template <typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p){
is >> p.first >> p.second;
return is;
}
template <typename T>
ostream &operator<<(ostream &os, vector<T> &v){
for (int i = 0; i < v.size(); ++i){
os << v[i] << (i + 1 != v.size() ? " " : "");
}
return os;
}
template <typename T>
ostream &operator<<(ostream &os, vector<vector<T>> &v){
for (int i = 0; i < v.size(); ++i){
os << v[i] << (i + 1 != v.size() ? "\n" : "");
}
return os;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &v){
for (int i = 0; i < v.size(); ++i) is >> v[i];
return is;
}
template <typename T>
ostream &operator<<(ostream &os, set<T> &v){
for (auto &u : v){
os << u << " ";
}
return os;
}
template<typename T1, typename T2>
vector<pair<T1, T2>> AssembleVectorPair(vector<T1> &v1, vector<T2> &v2){
assert(v1.size() == v2.size());
vector<pair<T1, T2>> v;
for(int i = 0; i < v1.size(); ++i) v.push_back({v1[i], v2[i]});
return v;
}
template<typename T1, typename T2>
pair<vector<T1>, vector<T2>> DisassembleVectorPair(vector<pair<T1, T2>> &v){
vector<T1> v1;
vector<T2> v2;
transform(v.begin(), v.end(), back_inserter(v1), [](auto p){return p.first;});
transform(v.begin(), v.end(), back_inserter(v2), [](auto p){return p.second;});
return {v1, v2};
}
template<typename T1, typename T2, typename T3>
tuple<vector<T1>, vector<T2>, vector<T3>> DisassembleVectorTuple(vector<tuple<T1, T2, T3>> &v){
vector<T1> v1;
vector<T2> v2;
vector<T3> v3;
transform(v.begin(), v.end(), back_inserter(v1), [](auto p){return get<0>(p);});
transform(v.begin(), v.end(), back_inserter(v2), [](auto p){return get<1>(p);});
transform(v.begin(), v.end(), back_inserter(v3), [](auto p){return get<2>(p);});
return {v1, v2, v3};
}
template<typename T1 = int, typename T2 = T1>
pair<vector<T1>, vector<T2>> InputVectorPair(int size){
vector<pair<T1, T2>> v(size);
for(auto &[p, q] : v) cin >> p >> q;
return DisassembleVectorPair(v);
}
template<typename T1 = int, typename T2 = T1, typename T3 = T1>
tuple<vector<T1>, vector<T2>, vector<T3>> InputVectorTuple(int size){
vector<tuple<T1, T2, T3>> v(size);
for(auto &[p, q, r] : v) cin >> p >> q >> r;
return DisassembleVectorTuple(v);
}
#line 2 "Library/DataStructure/WeightedUnionFind.hpp"
template<typename Abel = int32_t>
class WeightedUnionFind{
public:
WeightedUnionFind(int n) : data_(n, -1), weight_(n, Abel{}){}
int Find(const int k){
if(data_[k] < 0) return k;
int r = Find(data_[k]);
weight_[k] += weight_[data_[k]];
return data_[k] = r;
}
Abel Weight(const int k){
Find(k);
return weight_[k];
}
Abel Diff(const int x, const int y){
return Weight(y) - Weight(x);
}
bool Same(const int x, const int y){
return Find(x) == Find(y);
}
bool Unite(int x, int y, Abel w){
w += Weight(x) - Weight(y);
x = Find(x), y = Find(y);
if(x == y) return false;
if(data_[x] > data_[y]) swap(x, y), w = -w;
data_[x] += data_[y];
data_[y] = x;
weight_[y] = w;
return true;
}
private:
vector<int> data_;
vector<Abel> weight_;
};
#line 5 "verify/AOJ-DSL-1-B.test.cpp"
int main(){
cin.tie(0)->sync_with_stdio(false);
int n, q; cin >> n >> q;
WeightedUnionFind<ll> uf(n);
while(q--){
int query; cin >> query;
if(query == 0){
int x, y, z; cin >> x >> y >> z;
uf.Unite(x, y, z);
}
else{
int x, y; cin >> x >> y;
if(!uf.Same(x, y)) cout << "?" << '\n';
else cout << uf.Diff(x, y) << '\n';
}
}
}