#include <bits/stdc++.h>
using namespace std;
const int N = 2.5 * 1e4 + 5;
const int M = 5 * 1e4 + 5;
struct rec {
int x, y, z;
} e[M];
struct edge {
int v, w;
};
void read(int &x) {
int f = 1;
x = 0;
char c = getchar();
while (c < '0' || c > '9') {
if (c == '-')
f = -1;
c = getchar();
}
while (c >= '0' && c <= '9') {
x = (x << 1) + (x << 3) + (c ^ 48);
c = getchar();
}
x *= f;
}
int n, R, P, s, con[N], in[N], cnt;
long long dis[N];
bool vis[N], pos[N];
vector<edge> son[N];
vector<int> v[N];
priority_queue<pair<long long, int> > q;
void connect(int x) {
for (int i = 0; i < son[x].size(); i++) {
int y = son[x][i].v;
if (!con[y]) {
con[y] = cnt;
connect(y);
}
}
}
void dijkstra() {
for (int i = 1; i <= n; i++) dis[i] = 1e9;
dis[s] = 0;
q.push(make_pair(0, s));
while (q.size()) {
int x = q.top().second;
q.pop();
if (vis[x])
continue;
vis[x] = 1;
for (int i = 0; i < son[x].size(); i++) {
int y = son[x][i].v, w = son[x][i].w;
if (dis[x] + w < dis[y]) {
dis[y] = dis[x] + w;
if (con[x] == con[y])
q.push(make_pair(-dis[y], y));
}
if (con[x] != con[y]) {
in[con[y]]--;
if (!in[con[y]]) {
for (int i = 1; i <= n; i++)
if (con[i] == con[y] && pos[i])
q.push(make_pair(-dis[i], i));
}
}
}
}
}
void bfs() {
queue<int> que;
que.push(s);
pos[s] = 1;
while (que.size()) {
int x = que.front();
que.pop();
for (int i = 0; i < v[x].size(); i++) {
int y = v[x][i];
if (!pos[y]) {
pos[y] = 1;
que.push(y);
}
}
}
}
int main() {
read(n), read(R), read(P), read(s);
for (int i = 1; i <= R; i++) {
int x, y, z;
read(x), read(y), read(z);
son[x].push_back((edge){
y, z });
son[y].push_back((edge){
x, z });
v[x].push_back(y);
v[y].push_back(x);
}
for (int i = 1; i <= n; i++)
if (!con[i]) {
cnt++;
con[i]=cnt;
connect(i);
}
for (int i = 1; i <= P; i++) {
int x, y, z;
read(x), read(y), read(z);
v[x].push_back(y);
e[i] = (rec){
x, y, z };
}
bfs();
for (int i = 1; i <= P; i++) {
int x = e[i].x, y = e[i].y, z = e[i].z;
if (pos[x] && pos[y]) {
//能够与s联通
son[x].push_back((edge){
y, z });
in[con[y]]++;
}
}
dijkstra();
for (int i = 1; i <= n; i++) {
if (dis[i] == 1e9)
printf("NO PATH\n");
else
printf("%lld\n", dis[i]);
}
}
【题解】道路航线
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转载自blog.csdn.net/cqbzlydd/article/details/108088351
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