This documentation is automatically generated by online-judge-tools/verification-helper
#define PROBLEM "https://judge.yosupo.jp/problem/shortest_path"
#include"../../template/template.hpp"
#include"../../graph/graph_query.hpp"
int main(){
int n, m, s, t; in(n,m,s,t);
graph<ll> g(n,m);
rep(i,m){
int u, v; in(u,v);
ll c; in(c);
g.add_edge(u,v,c);
}
g.build();
auto dist = g.dijkstra(s);
if (dist[t] == g.dist_inf){
out(-1);
return 0;
}
auto ans = g.reconstruct(s,t,dist);
out(dist[t],ans.size()-1);
rep(i,ans.size()-1) out(ans[i],ans[i+1]);
}
#line 1 "test/graph/Shortest_Path2.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/shortest_path"
#line 2 "template/template.hpp"
using namespace std;
#include<bits/stdc++.h>
#line 1 "template/inout_old.hpp"
namespace noya2 {
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p){
os << p.first << " " << p.second;
return os;
}
template <typename T, typename U>
istream &operator>>(istream &is, pair<T, U> &p){
is >> p.first >> p.second;
return is;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v){
int s = (int)v.size();
for (int i = 0; i < s; i++) os << (i ? " " : "") << v[i];
return os;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &v){
for (auto &x : v) is >> x;
return is;
}
void in() {}
template <typename T, class... U>
void in(T &t, U &...u){
cin >> t;
in(u...);
}
void out() { cout << "\n"; }
template <typename T, class... U, char sep = ' '>
void out(const T &t, const U &...u){
cout << t;
if (sizeof...(u)) cout << sep;
out(u...);
}
template<typename T>
void out(const vector<vector<T>> &vv){
int s = (int)vv.size();
for (int i = 0; i < s; i++) out(vv[i]);
}
struct IoSetup {
IoSetup(){
cin.tie(nullptr);
ios::sync_with_stdio(false);
cout << fixed << setprecision(15);
cerr << fixed << setprecision(7);
}
} iosetup_noya2;
} // namespace noya2
#line 1 "template/const.hpp"
namespace noya2{
const int iinf = 1'000'000'007;
const long long linf = 2'000'000'000'000'000'000LL;
const long long mod998 = 998244353;
const long long mod107 = 1000000007;
const long double pi = 3.14159265358979323;
const vector<int> dx = {0,1,0,-1,1,1,-1,-1};
const vector<int> dy = {1,0,-1,0,1,-1,-1,1};
const string ALP = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const string alp = "abcdefghijklmnopqrstuvwxyz";
const string NUM = "0123456789";
void yes(){ cout << "Yes\n"; }
void no(){ cout << "No\n"; }
void YES(){ cout << "YES\n"; }
void NO(){ cout << "NO\n"; }
void yn(bool t){ t ? yes() : no(); }
void YN(bool t){ t ? YES() : NO(); }
} // namespace noya2
#line 2 "template/utils.hpp"
#line 6 "template/utils.hpp"
namespace noya2{
unsigned long long inner_binary_gcd(unsigned long long a, unsigned long long b){
if (a == 0 || b == 0) return a + b;
int n = __builtin_ctzll(a); a >>= n;
int m = __builtin_ctzll(b); b >>= m;
while (a != b) {
int mm = __builtin_ctzll(a - b);
bool f = a > b;
unsigned long long c = f ? a : b;
b = f ? b : a;
a = (c - b) >> mm;
}
return a << std::min(n, m);
}
template<typename T> T gcd_fast(T a, T b){ return static_cast<T>(inner_binary_gcd(std::abs(a),std::abs(b))); }
long long sqrt_fast(long long n) {
if (n <= 0) return 0;
long long x = sqrt(n);
while ((x + 1) * (x + 1) <= n) x++;
while (x * x > n) x--;
return x;
}
template<typename T> T floor_div(const T n, const T d) {
assert(d != 0);
return n / d - static_cast<T>((n ^ d) < 0 && n % d != 0);
}
template<typename T> T ceil_div(const T n, const T d) {
assert(d != 0);
return n / d + static_cast<T>((n ^ d) >= 0 && n % d != 0);
}
template<typename T> void uniq(std::vector<T> &v){
std::sort(v.begin(),v.end());
v.erase(unique(v.begin(),v.end()),v.end());
}
template <typename T, typename U> inline bool chmin(T &x, U y) { return (y < x) ? (x = y, true) : false; }
template <typename T, typename U> inline bool chmax(T &x, U y) { return (x < y) ? (x = y, true) : false; }
template<typename T> inline bool range(T l, T x, T r){ return l <= x && x < r; }
} // namespace noya2
#line 8 "template/template.hpp"
#define rep(i,n) for (int i = 0; i < (int)(n); i++)
#define repp(i,m,n) for (int i = (m); i < (int)(n); i++)
#define reb(i,n) for (int i = (int)(n-1); i >= 0; i--)
#define all(v) (v).begin(),(v).end()
using ll = long long;
using ld = long double;
using uint = unsigned int;
using ull = unsigned long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using pil = pair<int,ll>;
using pli = pair<ll,int>;
namespace noya2{
/* ~ (. _________ . /) */
}
using namespace noya2;
#line 2 "graph/graph_query.hpp"
#line 2 "data_structure/csr.hpp"
#line 4 "data_structure/csr.hpp"
#include<ranges>
#line 7 "data_structure/csr.hpp"
namespace noya2::internal {
template<class E>
struct csr {
csr () {}
csr (int _n) : n(_n) {}
csr (int _n, int m) : n(_n){
start.reserve(m);
elist.reserve(m);
}
// ACL style constructor (do not have to call build)
csr (int _n, const std::vector<std::pair<int,E>> &idx_elem) : n(_n), start(_n + 2), elist(idx_elem.size()) {
for (auto &[i, e] : idx_elem){
start[i + 2]++;
}
for (int i = 1; i < n; i++){
start[i + 2] += start[i + 1];
}
for (auto &[i, e] : idx_elem){
elist[start[i + 1]++] = e;
}
prepared = true;
}
int add(int idx, E elem){
int eid = start.size();
start.emplace_back(idx);
elist.emplace_back(elem);
return eid;
}
void build(){
if (prepared) return ;
int m = start.size();
std::vector<E> nelist(m);
std::vector<int> nstart(n + 2, 0);
for (int i = 0; i < m; i++){
nstart[start[i] + 2]++;
}
for (int i = 1; i < n; i++){
nstart[i + 2] += nstart[i + 1];
}
for (int i = 0; i < m; i++){
nelist[nstart[start[i] + 1]++] = elist[i];
}
swap(elist,nelist);
swap(start,nstart);
prepared = true;
}
const auto operator[](int idx) const {
return std::ranges::subrange(elist.begin()+start[idx],elist.begin()+start[idx+1]);
}
auto operator[](int idx){
return std::ranges::subrange(elist.begin()+start[idx],elist.begin()+start[idx+1]);
}
const auto operator()(int idx, int l, int r) const {
return std::ranges::subrange(elist.begin()+start[idx]+l,elist.begin()+start[idx]+r);
}
auto operator()(int idx, int l, int r){
return std::ranges::subrange(elist.begin()+start[idx]+l,elist.begin()+start[idx]+r);
}
size_t size() const {
return n;
}
int n;
std::vector<int> start;
std::vector<E> elist;
bool prepared = false;
};
} // namespace noya2::internal
#line 2 "graph/unweighted_type.hpp"
namespace noya2 {
struct unweighted {};
} // namespace noya2
#line 6 "graph/graph_query.hpp"
#line 12 "graph/graph_query.hpp"
namespace noya2 {
template<typename Cost>
struct graph {
int n;
internal::csr<std::pair<int,Cost>> g;
Cost dist_inf = std::numeric_limits<Cost>::max() / 3;
graph (int _n = 0) : n(_n), g(_n) {}
graph (int _n, int _m) : n(_n), g(_n,_m) {}
// 有向辺を追加 (無向辺ではないことに注意!)
int add_edge(int u, int v, Cost cost = 1){
int id = g.add(u, {v,cost});
return id;
}
template<bool directed>
static graph input(int _n, int _m, int indexed = 1){
if constexpr (directed){
graph g(_n, _m*2);
for (int i = 0; i < _m; i++){
int u, v; std::cin >> u >> v;
u -= indexed, v -= indexed;
Cost c; std::cin >> c;
g.add_edge(u, v, c);
g.add_edge(v, u, c);
}
g.build();
return g;
}
else {
graph g(_n, _m);
for (int i = 0; i < _m; i++){
int u, v; std::cin >> u >> v;
u -= indexed, v -= indexed;
Cost c; std::cin >> c;
g.add_edge(u, v, c);
}
g.build();
return g;
}
}
void build(){
g.build();
}
void set_inf(Cost new_inf){
dist_inf = new_inf;
}
std::vector<Cost> dijkstra(int s){
g.build();
std::vector<Cost> dist(n,dist_inf);
dist[s] = 0;
using P = std::pair<Cost,int>;
std::priority_queue<P,std::vector<P>,std::greater<P>> pque;
pque.push(P(0,s));
while (!pque.empty()){
auto [d, v] = pque.top(); pque.pop();
if (dist[v] < d) continue;
for (auto [u, c] : g[v]){
if (chmin(dist[u],d+c)){
pque.push(P(dist[u],u));
}
}
}
return dist;
}
std::vector<int> reconstruct(int s, int t, const std::vector<Cost> &dist){
if (dist[t] == dist_inf) return {};
g.build();
std::vector<int> from(n,-1);
std::queue<int> que;
que.push(s);
while (!que.empty()){
int v = que.front(); que.pop();
for (auto [u, c] : g[v]){
if (from[u] == -1 && dist[u] == dist[v] + c){
from[u] = v;
que.push(u);
}
}
}
std::vector<int> ans = {t};
while (t != s){
t = from[t];
ans.emplace_back(t);
}
std::reverse(ans.begin(),ans.end());
return ans;
}
std::vector<Cost> bfs01(int s){
g.build();
std::vector<Cost> dist(n,dist_inf);
dist[s] = 0;
std::deque<int> que;
que.push_back(s);
while (!que.empty()){
int v = que.front(); que.pop_front();
for (auto [u, c] : g[v]){
if (chmin(dist[u],dist[v]+c)){
if (c == 0) que.push_front(u);
else que.push_back(u);
}
}
}
return dist;
}
std::vector<Cost> bfs1(int s){
g.build();
std::vector<Cost> dist(n,dist_inf);
dist[s] = 0;
std::queue<int> que;
que.push(s);
while (!que.empty()){
int v = que.front(); que.pop();
for (auto [u, c] : g[v]){
if (chmin(dist[u],dist[v]+c)){
que.push(u);
}
}
}
return dist;
}
std::vector<Cost> bellman_ford(int s, bool &ng_cycle){
g.build();
std::vector<Cost> dist(n,dist_inf);
std::vector<int> ng;
dist[s] = 0;
int tm = 0;
while (tm < n){
bool finish = true;
for (int v = 0; v < n; v++){
if (dist[v] == dist_inf) continue;
for (auto [u, c] : g[v]){
if (chmin(dist[u],dist[v]+c)){
finish = false;
if (tm == n-1) ng.emplace_back(u);
}
}
}
if (finish) break;
tm++;
}
ng_cycle = (tm == n);
if (ng_cycle){
for (auto v : ng) dist[v] = -dist_inf;
tm = n;
while (tm--){
for (int v = 0; v < n; v++){
if (dist[v] != -dist_inf) continue;
for (auto [u, c] : g[v]){
dist[u] = -dist_inf;
}
}
}
}
return dist;
}
std::vector<std::vector<Cost>> warshall_floyd(){
g.build();
std::vector<std::vector<Cost>> dist(n,std::vector<Cost>(n,dist_inf));
for (int v = 0; v < n; v++){
dist[v][v] = 0;
for (auto [u, c] : g[v]){
chmin(dist[v][u],c);
}
}
for (int k = 0; k < n; k++){
for (int i = 0; i < n; i++){
for (int j = 0; j < n; j++){
chmin(dist[i][j],dist[i][k]+dist[k][j]);
}
}
}
return dist;
}
const auto operator[](int idx) const { return g[idx]; }
auto operator[](int idx) { return g[idx]; }
};
template<>
struct graph<unweighted> {
int n;
internal::csr<int> g;
int dist_inf = std::numeric_limits<int>::max() / 2;
graph (int _n = 0) : n(_n), g(_n) {}
graph (int _n, int _m) : n(_n), g(_n,_m) {}
// 有向辺を追加 (無向辺ではないことに注意!)
int add_edge(int u, int v){
int id = g.add(u, v);
return id;
}
template<bool directed>
static graph input(int _n, int _m, int indexed = 1){
if constexpr (directed){
graph g(_n, _m*2);
for (int i = 0; i < _m; i++){
int u, v; std::cin >> u >> v;
u -= indexed, v -= indexed;
g.add_edge(u, v);
g.add_edge(v, u);
}
g.build();
return g;
}
else {
graph g(_n, _m);
for (int i = 0; i < _m; i++){
int u, v; std::cin >> u >> v;
u -= indexed, v -= indexed;
g.add_edge(u, v);
}
g.build();
return g;
}
}
void build(){
g.build();
}
void set_inf(int new_inf){
dist_inf = new_inf;
}
std::vector<int> reconstruct(int s, int t, const std::vector<int> &dist){
if (dist[t] == dist_inf) return {};
g.build();
std::vector<int> from(n,-1);
std::queue<int> que;
que.push(s);
while (!que.empty()){
int v = que.front(); que.pop();
for (auto u : g[v]){
if (from[u] == -1 && dist[u] == dist[v] + 1){
from[u] = v;
que.push(u);
}
}
}
std::vector<int> ans = {t};
while (t != s){
t = from[t];
ans.emplace_back(t);
}
std::reverse(ans.begin(),ans.end());
return ans;
}
std::vector<int> bfs(int s){
g.build();
std::vector<int> dist(n,dist_inf);
dist[s] = 0;
std::queue<int> que;
que.push(s);
while (!que.empty()){
int v = que.front(); que.pop();
for (auto u : g[v]){
if (chmin(dist[u],dist[v]+1)){
que.push(u);
}
}
}
return dist;
}
const auto operator[](int idx) const { return g[idx]; }
auto operator[](int idx) { return g[idx]; }
};
template<>
struct graph<bool> {
int n;
internal::csr<std::pair<int,bool>> g;
int dist_inf = std::numeric_limits<int>::max() / 2;
graph (int _n = 0) : n(_n), g(_n) {}
graph (int _n, int _m) : n(_n), g(_n,_m) {}
// 有向辺を追加 (無向辺ではないことに注意!)
int add_edge(int u, int v, bool cost){
int id = g.add(u, {v, cost});
return id;
}
void build(){
g.build();
}
void set_inf(int new_inf){
dist_inf = new_inf;
}
std::vector<int> reconstruct(int s, int t, const std::vector<int> &dist){
if (dist[t] == dist_inf) return {};
g.build();
std::vector<int> from(n,-1);
std::queue<int> que;
que.push(s);
while (!que.empty()){
int v = que.front(); que.pop();
for (auto [u, b] : g[v]){
int c = (int)b;
if (from[u] == -1 && dist[u] == dist[v] + c){
from[u] = v;
que.push(u);
}
}
}
std::vector<int> ans = {t};
while (t != s){
t = from[t];
ans.emplace_back(t);
}
std::reverse(ans.begin(),ans.end());
return ans;
}
std::vector<int> bfs01(int s){
g.build();
std::vector<int> dist(n,dist_inf);
dist[s] = 0;
std::deque<int> que;
que.push_back(s);
while (!que.empty()){
int v = que.front(); que.pop_front();
for (auto [u, b] : g[v]){
int c = (int)b;
if (chmin(dist[u],dist[v]+c)){
if (c == 0) que.push_front(u);
else que.push_back(u);
}
}
}
return dist;
}
const auto operator[](int idx) const { return g[idx]; }
auto operator[](int idx) { return g[idx]; }
};
} // namespace noya2
#line 5 "test/graph/Shortest_Path2.test.cpp"
int main(){
int n, m, s, t; in(n,m,s,t);
graph<ll> g(n,m);
rep(i,m){
int u, v; in(u,v);
ll c; in(c);
g.add_edge(u,v,c);
}
g.build();
auto dist = g.dijkstra(s);
if (dist[t] == g.dist_inf){
out(-1);
return 0;
}
auto ans = g.reconstruct(s,t,dist);
out(dist[t],ans.size()-1);
rep(i,ans.size()-1) out(ans[i],ans[i+1]);
}