【一个蒟蒻的挣扎】单源最短路（Dijkstra）

赛前没啥时间好好解释了，还有三天2019CSP，大家加油啊！！！

ヾ(◍°∇°◍)ﾉﾞ

背掉它就好啦！！！

我觉得我这一版打得还行就放上来了

#include<cstdio>
#include<cstring>
#include<iostream>
#include<queue>
#include<cmath>
#include<vector>
using namespace std;
int n,m,s;
int dis[10001],first[10001];
inline void read(int &x)
{
    char c=getchar();
    int flag=1; x=0;
    while (c<'0'||c>'9')
    {
        if (c=='-') flag=-1;
        c=getchar();
    }
    while (c>='0'&&c<='9')
    {
        x=x*10+c-'0';
        c=getchar();
    }
    x*=flag;
}
struct edge
{
    int next,to,v;
    edge()
    {
    }
    edge(int a,int b,int c)
    {
        next=a; to=b; v=c;
    }
}E[10004];
struct heap
{
    int to,v;
    heap()
    {
    }
    heap(int a,int b)
    {
        to=a; v=b;
    }
};
priority_queue<heap> h;
inline bool operator < (const heap &a,const heap &b)
{
    return a.v>b.v;
}
int tot;
void add_to_edge(int a,int b,int c)
{
    E[++tot]=edge(first[a],b,c);
     first[a]=tot;
}
void add_to_heap(int p)
{
    for (int i=first[p]; i; i=E[i].next)
    {
        if (dis[E[i].to]==-1)
        h.push(heap(E[i].to,dis[p]+E[i].v)); 
    } 
}
void dijkstra(int s)
{
    while (!h.empty())
    {
        h.pop();
    }
    memset(dis,-1,sizeof(dis));
    dis[s]=0;
    add_to_heap(s);
    while (!h.empty())
    {
        if (dis[h.top().to]!=-1)
        {
            h.pop();
            continue;
        }
        int p=h.top().to;
        dis[p]=h.top().v;
        h.pop();
        add_to_heap(p);
    }
}
int main()
{
    read(n); read(m); read(s);
    for (int i=1; i<=m; i++)
    {
        int x,y,z;
        read(x); read(y); read(z);
        add_to_edge(x,y,z);
    }
    dijkstra(s);
    for (int i=1; i<=n; i++)
    cout<<dis[i]<<" ";
    return 0;
}

2019CSP-S    RP+++++