最短路径 还原路径(dijkstra算法)

#include<iostream>#include<cstring>#include<cstdlib>#include<algorithm>#include<cctype>#include<cmath>#include<ctime>#include<string>#include<stack>#include<deque>#include<queue>#include<list>#include<set>#include<map>#include<cstdio>#include<limits.h>#define MOD 1000000007#define fir first#define sec second#define fin freopen("/home/ostreambaba/文档/input.txt", "r", stdin)#define fout freopen("/home/ostreambaba/文档/output.txt", "w", stdout)#define mes(x, m) memset(x, m, sizeof(x))#define Pii pair<int, int>#define Pll pair<ll, ll>#define INF 1e9+7#define inf 0x3f3f3f3f#define Pi 4.0*atan(1.0)#define lowbit(x) (x&(-x))#define lson l,m,rt<<1#define rson m+1,r,rt<<1|1#define max(a,b) a>b?a:btypedef long long ll;typedef unsigned long long ull;const double eps = 1e-9;const int maxn = 1e3;const int maxm = 1e3+10;using namespace std;inline 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;}struct edge{    int to,w,next;}g[maxn];int head[maxn];bool vis[maxn];int dis[maxn];int pre[maxn];int tot;void init(){    tot=0;    mes(head,-1);}inline void addEdge(int u,int v,int w){    g[tot].next=head[u];    g[tot].to=v;    g[tot].w=w;    head[u]=tot++;}void dijkstra(int s,int n){    priority_queue<Pii,vector<Pii>,greater<Pii> >que;    fill(dis,dis+n+1,inf);    fill(vis,vis+n+1,false);    fill(pre,pre+n+1,-1);    dis[s]=0;    vis[s]=true;    que.push(make_pair(0,s));    while(!que.empty()){        Pii p=que.top();        que.pop();        int u=p.second;        for(int i=head[u];~i;i=g[i].next){ //u->v            int v=g[i].to;            int w=g[i].next;            if(!vis[v]&&dis[v]>dis[u]+w){                dis[v]=dis[u]+w;                vis[v]=true;                que.push(make_pair(vis[v],v));                pre[v]=u;　//用pre数组记录 u的前驱节点为v            }        }    }}stack<int> path(int t){    stack<int> st;    for(;t!=-1;t=pre[t]){        st.push(t);    }    return st;}int main(){   // fin;    init();    int n,m;    cin>>n>>m;    int u,v,w;    while(m--){        cin>>u>>v>>w;        addEdge(u,v,w);        addEdge(v,u,w);    }    dijkstra(0,n);    int t;    cin>>t;    stack<int> st=path(t);    while(!st.empty()){        cout<<st.top()<<" ";        st.pop();    }    cout<<endl;}