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| #include <algorithm>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <fstream>
#include <iostream>
#include <vector>
using namespace std;
typedef long long int64;
const int MAXN = 100010;
const int INF = 0x3f3f3f3f;
#include <cctype>
#include <cstdio>
template <typename T = int>
inline T read() {
T X = 0, w = 0;
char ch = 0;
while (!isdigit(ch)) {
w |= ch == '-';
ch = getchar();
}
while (isdigit(ch)) {
X = (X << 3) + (X << 1) + (ch ^ 48);
ch = getchar();
}
return w ? -X : X;
}
template <typename T>
inline void write(T x) {
if (x < 0) putchar('-'), x = -x;
if (x > 9) write(x / 10);
putchar(x % 10 + '0');
}
class lfs {
public:
lfs(int N) {
memset(head, -1, sizeof head);
ecnt = 0;
n = N;
}
void adde(int from, int to, int w) {
e[ecnt].to = to;
e[ecnt].w = w;
e[ecnt].next = head[from];
head[from] = ecnt++;
}
void addde(int a, int b, int w) {
adde(a, b, w);
adde(b, a, w);
}
void solve() {
vector<int> bfs_order;
memset(dis, INF, sizeof dis);
dis[0] = 0;
bfs_order.push_back(0);
int cur = 0;
while (cur < bfs_order.size()) {
int u = bfs_order[cur];
for (int i = head[u]; i != -1; i = e[i].next) {
int v = e[i].to;
if (dis[v] == INF) {
dis[v] = dis[u] + 1;
bfs_order.push_back(v);
}
}
cur++;
}
vector<int> end_point;
end_point.push_back(n - 1);
memset(vis, false, sizeof vis);
memset(pre, 0, sizeof pre);
vis[n - 1] = true;
cur = 0;
int mindis = dis[n - 1];
while (cur < end_point.size()) {
int u = end_point[cur];
for (int i = head[u]; i != -1; i = e[i].next) {
int v = e[i].to;
if (e[i].w == 0 && !vis[v]) {
end_point.push_back(v);
pre[v] = u;
vis[v] = true;
mindis = min(mindis, dis[v]);
}
}
cur++;
}
bool leading_zeros = true;
for (int l = mindis; l > 0; l--) {
int now = INF;
vector<int> next_point;
for (auto& u : end_point) {
for (int i = head[u]; i != -1; i = e[i].next) {
int v = e[i].to;
if (dis[v] + 1 == l) {
now = min(now, e[i].w);
}
}
}
if (now != 0) leading_zeros = false;
if (l == 1 || !leading_zeros) cout << now;
for (auto& u : end_point) {
for (int i = head[u]; i != -1; i = e[i].next) {
int v = e[i].to;
if (dis[v] + 1 == l && e[i].w == now && !vis[v]) {
vis[v] = true;
next_point.push_back(v);
pre[v] = u;
}
}
}
end_point = next_point;
}
if (leading_zeros) cout << 0;
cout << endl;
vector<int> path;
int u = 0;
path.push_back(u);
while (u != n - 1) {
u = pre[u];
path.push_back(u);
}
cout << path.size() << endl;
for (auto& i : path) {
cout << i << ' ';
}
cout << endl;
}
protected:
struct Edge {
int to, next, w;
} e[MAXN * 2];
int head[MAXN];
int ecnt;
int n;
int dis[MAXN];
bool vis[MAXN];
int pre[MAXN];
};
int main() {
int n = read();
int m = read();
auto graph = new lfs(n);
for (int i = 1; i <= m; i++) {
int u = read();
int v = read();
int w = read();
graph->addde(u, v, w);
}
graph->solve();
}
|
