[模板] Dijkstra(堆优化)算法求最短路

微机做完实验然后写了一发Dijkstra

代码如下：

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <queue>
using namespace std;
const int maxn = 3000;
const int maxm = 1000000+10;
const long int INF = 0x3f3f3f3f;
bool vis[maxn];
long int Dis[maxn];
struct Node{
	int id;
	long int dis;
	Node(int _id=0,int _dis=0):id(_id),dis(_dis){}
	bool operator < (const Node &rhs)const{
		return dis > rhs.dis;
	}
};
struct Edge{
	int from,to,Next;
	long int d;
	Edge(){}
	Edge(int f,int t,int N,int dd)
	{	
		from  = f;
		to = t;
		Next = N;
		d = dd;
	}
};
struct Edge edge[maxm];
int head[maxn],tot;
void initEdge()
{
	memset(head,-1,sizeof(head));
	tot = 0;
}
void addedge(int u,int v,long int d)
{
	edge[tot].to = v;
	edge[tot].d = d;
	edge[tot].Next = head[u];
	head[u] = tot++;
}

void Dijkstra(int st,int n)
{
	priority_queue<Node> Q;
	int i;
	for(i=0;i<=n;++i)
		vis[i] = false, Dis[i] = INF;
	Dis[st] = 0;
	Q.push(Node(st,0));
	while(!Q.empty())
	{
		int now = Q.top().id;
		int ndis = Q.top().dis;
		Q.pop();
		if(vis[now]) continue;
		vis[now] = true;
		for(int i=head[now]; i!=-1; i=edge[i].Next){
			int to = edge[i].to;
			long int d = edge[i].d;
			if(!vis[to] && ndis+d<Dis[to])
			{
				Dis[to] = ndis+d;
				Q.push(Node(to,Dis[to]));	
			}
		}	
	}
	printf("The minist distance to Node(%d) from every node is as follow:\n",st);
	for(i=1;i<=n;++i)
	{
		if(i==st) continue;
		printf("Dis[%2d] = %4ld\n",i,Dis[i]);
	}
	char s1[2000];
	printf("Input any string to quit:");
	scanf("%s",s1);
	

}
int main()
{
	printf("Marry Christmas\n");
	int n,m,u,v;
	long int d;
	printf("Please input the number of nodes and the number of edges: _ _\b\b\b");
	scanf("%d%d",&n,&m);
	initEdge();
	int st = 1000000000;
	for(int i=1;i<=m;++i)
	{
		printf("Please input start_node_ID,end_node_ID,edge_length of edge %d: _ _ _\b\b\b\b\b",i);
		scanf("%d%d%ld",&u,&v,&d);
		if(st>u) st = u;
		if(st>v) st = v;
		addedge(u,v,d);
		addedge(v,u,d);
	}
	int _st;
	printf("Please input the source_node_ID(1-%d): _\b",n);
	scanf("%d",&_st);
	if(_st<1||_st>n) _st = st;
	Dijkstra(_st,n);


	return 0;
}  

Marry Christmas!

xzc 2019.12.25