关于Dij

#include<bits/stdc++.h>
using namespace std;
#define float double
#define mian main
#define ture true
int n,grf[1001][1001],dis[1001];
int read()
{
    int x=0,f=1;
    char ch=getchar();
    while(ch<'0'||ch>'9')
    {
        if(ch=='-')f=-1;
        ch=getchar();
    }
    while(ch>='0'&&ch<='9')
    {
        x=x*10+ch-'0';
        ch=getchar();
    }
    return x*f;
}
void write(int x)
{
    if(x<0)
    {
        putchar('-');
        x=-x;
    }
    if(x>9)write(x/10);
    putchar(x%10+'0');
}
void dfs(int k)
{
    for(int i=0;i<n;i++)
    {
        if(grf[k][i]!=0x3f3f3f3f)
        {
            dis[i]=min(dis[i],dis[k]+grf[k][i]);
            dfs(i);
        }
    }
}
int main()
{
    int m,u,v,q;
    memset(grf,0x3f,sizeof(grf));
    n=read();m=read();
    for(int i=0;i<m;i++)
    {
        u=read();v=read();q=read();
        grf[u][v]=q;
    }
    for(int i=0;i<n;i++)grf[i][i]=0;
    dfs(0);
    cout<<dis[n-1];
    return 0;
}