dijkstra+堆优化(早年产物2020.11.6)

#include <fstream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <queue> 
using namespace std;
int n,m,point[1001],last[2001],cnt,dis[1001],vis[1001];
bool inq[1001];
struct nn{
	int y,v;
}r[2001];
typedef pair<int,int> node;
/*struct node{
	int d,x;
	bool operator < (const node &p)const{
		return d > p.d;
	}
};*/
priority_queue <node,vector<node>,greater<node> > q;
void add(int x,int y,int v){
	cnt++;
	last[cnt] = point[x];
	point[x] = cnt;
	r[cnt].y = y,r[cnt].v = v;
}
void dij(){
	q.push(node(0,1));
	dis[1] = 0;
	int i,v;
	while(!q.empty()){
		v = q.top().second;
		vis[v] = 1;
		q.pop();
		//printf("%d %d",dis[v],point[v]);
		inq[v] = false;
		for (i = point[v]; i; i = last[i]){
			//printf("%d ",r[i].y);
			if(dis[v] + r[i].v < dis[r[i].y] && vis[r[i].y] == false){
				dis[r[i].y] = dis[v] + r[i].v;
				//printf("%d ",dis[r[i].y]);
				if(!inq[r[i].y]){
					q.push(node(dis[r[i].y],r[i].y));
					inq[r[i].y] = true;
				}
			}
		}
	}
}
int main(){
	freopen("cin.in","r",stdin);
	freopen("out.out","w",stdout);
	
	memset(dis,0x3f,sizeof(dis));
	scanf("%d%d",&n,&m);
	int x,y,v;
	for (int i = 1; i <= m; i++){
		scanf("%d%d%d",&x,&y,&v);
		add(x,y,v),add(y,x,v);
	}
	dij();
	printf("%d",dis[n]);
	fclose(stdin);
	fclose(stdout);
	return 0;
}