#include<cstdio> #include<string> #include<cstdlib> #include<cmath> #include<iostream> #include<cstring> #include<set> #include<queue> #include<algorithm> #include<vector> #include<map> #include<cctype> #include<stack> #include<sstream> #include<list> #include<assert.h> #include<bitset> #include<numeric> #define debug() puts("++++") #define gcd(a,b) __gcd(a,b) #define lson l,m,rt<<1 #define rson m+1,r,rt<<1|1 #define fi first #define se second #define pb push_back #define sqr(x) ((x)*(x)) #define ms(a,b) memset(a,b,sizeof(a)) #define sz size() #define be begin() #define pu push_up #define pd push_down #define cl clear() #define lowbit(x) -x&x #define all 1,n,1 #define rep(i,x,n) for(int i=(x); i<(n); i++) #define in freopen("in.in","r",stdin) #define out freopen("out.out","w",stdout) using namespace std; typedef long long LL; typedef unsigned long long ULL; typedef pair<int,int> P; const int INF = 0x3f3f3f3f; const LL LNF = 1e18; const int maxn = 1e5+10; const int maxm = 1e6+10; const double PI = acos(-1.0); const double eps = 1e-8; const int dx[] = {-1,1,0,0,1,1,-1,-1}; const int dy[] = {0,0,1,-1,1,-1,1,-1}; int dir[4][2] = {{0,1},{0,-1},{-1,0},{1,0}}; const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; int head[maxn],vis[maxn],dis[maxn]; int t,n,m,u,v,w,st,ed; struct node { int v,w,nxt; }e[maxn<<1]; /*struct cmp { bool operator()(int a,int b) { return dis[a]>dis[b]; } };*/ int tot=0; void init() { tot=0; ms(head,-1); ms(vis,0); ms(dis,INF); } void add(int u,int v,int w) { e[tot].v=v; e[tot].w=w; e[tot].nxt=head[u]; head[u]=tot++; } void dij(int s,int t) { priority_queue< pair<int,int> > q; dis[s]=0; q.push(make_pair(0,s)); while(!q.empty()) { int u = q.top().second; q.pop(); for(int i=head[u];i!=-1;i=e[i].nxt) { int v = e[i].v; if(dis[v]>dis[u]+e[i].w) { dis[v]=dis[u]+e[i].w; q.push(make_pair(-dis[v],v)); } } } int ans=dis[t]; if(ans!=INF) printf("%d ",ans); else puts("-1"); } int main() { while(~scanf("%d%d",&n,&m)) { init(); for(int i=0;i<m;i++) { scanf("%d%d%d",&u,&v,&w); add(u,v,w); add(v,u,w); } scanf("%d%d",&st,&ed); dij(st,ed); } } /* 【题意】 【类型】 【分析】 【时间复杂度&&优化】 【trick】 【数据】 */