c++ Dijsktra算法鄰接表版本和鏈式前向星版本的實現（堆優化版本）

鄰接表版本

#include <iostream>
#include <queue>
#include <cstring>
#include <algorithm>
#include <cstdio>
#include <limits.h>
const int INF = 0x3f3f3f3f;
const int MAXN = 100010;
const int MAXM = 200020;
using namespace std;
struct Vertex {
	int pos;
	int dist;
	Vertex * next;
	Vertex(const int & _pos = int(), const int & _dist = int(), Vertex * _next = nullptr) : pos(_pos), dist(_dist), next(_next) {}
} vtx[MAXN];
struct Node {
	int dist;
	int pos;
	Node(const int & _dist = int(), const int & _pos = int()) :dist(_dist), pos(_pos) {}
	bool operator<(const Node & another) const {
		return another.dist < dist;
	}
};
int dist[MAXN];
int visit[MAXN];
void dijkstra(const int & st) {
	dist[st] = 0;
	priority_queue<Node> q;
	q.push(Node(0, st));
	while (!q.empty()) {
		Node tmp = q.top();
		q.pop();
		int x = tmp.pos;
		if (visit[x]) {
			continue;
		}
		visit[x] = 1;
		for (Vertex * v = vtx[x].next; v; v = v->next) {
			int y = v->pos;
			if (dist[y] > dist[x] + v->dist) {
				dist[y] = dist[x] + v->dist;
				if (!visit[y]) {
					q.push(Node(dist[y], y));
				}
			}
		}
	}
}
inline void addEdge(const int & u, const int & v, const int & w) {
	Vertex * newVtx = new Vertex(v, w);
	newVtx->next = vtx[u].next;
	vtx[u].next = newVtx;
}
int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n, m, s;
	cin >> n >> m >> s;
	memset(dist, INF, sizeof(dist));
	for (register int i = 1; i <= m; ++i) {
		register int u, v, w;
		cin >> u >> v >> w;
		addEdge(u, v, w);
	}
	dijkstra(s);
	for (int i = 1; i <= n; ++i) {
		if (!visit[i]) {
			cout << INT_MAX << ' ';
		}
		else {
			cout << dist[i] << ' ';
		}
	}
	return 0;
}

鏈式前向星版本

#include <iostream>
#include <queue>
#include <cstring>
#include <algorithm>
#include <cstdio>
#include <limits.h>
const int INF = 0x3f3f3f3f;
const int MAXN = 100010;
const int MAXM = 200020;
using namespace std;
struct Edge {
	int to, next, w;
	Edge(const int & _to = int(), const int & _next = int(), const int & _w = int()) : to(_to), next(_next), w(_w) {}
} edge[MAXM];
struct Node {
	int dist;
	int pos;
	Node(const int & _dist = int(), const int & _pos = int()) :dist(_dist), pos(_pos) {}
	bool operator<(const Node & another) const {
		return another.dist < dist;
	}
};
int dist[MAXN];
int visit[MAXN];
int head[MAXN];
int cnt;
void dijkstra(const int & st) {
	dist[st] = 0;
	priority_queue<Node> q;
	q.push(Node(0, st));
	while (!q.empty()) {
		Node tmp = q.top();
		q.pop();
		int x = tmp.pos;
		if (visit[x]) {
			continue;
		}
		visit[x] = 1;
		for (int i = head[x]; i;i = edge[i].next) {
			int y = edge[i].to;
			if (dist[y] > dist[x] + edge[i].w) {
				dist[y] = dist[x] + edge[i].w;
				if (!visit[y]) {
					q.push(Node(dist[y], y));
				}
			}
		}
	}
}
inline void addEdge(const int & u, const int & v, const int & w) {
	++cnt;
	edge[cnt].to = v;
	edge[cnt].next = head[u];
	edge[cnt].w = w;
	head[u] = cnt;
}
int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n, m, s;
	cin >> n >> m >> s;
	memset(dist, INF, sizeof(dist));
	for (register int i = 1; i <= m; ++i) {
		register int u, v, w;
		cin >> u >> v >> w;
		addEdge(u, v, w);
	}
	dijkstra(s);
	for (int i = 1; i <= n; ++i) {
		if (!visit[i]) {
			cout << INT_MAX << ' ';
		}
		else {
			cout << dist[i] << ' ';
		}
	}
	return 0;
}