21.cpp

#include<bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=a;i<b;++i)
#define IFOR(i,a,b) for(int i=a-1;i>=b;--i)
#define IO ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define ll long long
#define F first
#define S second
#define pb emplace_back 
#define vi vector<int>
#define vll vector<ll>
#define vvi vector<vi>
#define vvll vector<vll>
#define pii pair<int,int>
#define pll pair<ll,ll>
#define BE(a) a.begin(),a.end()
#define DIM(S) template<typename T> struct Dim<S<T>>{ enum {val = 1 + Dim<T>::val}; };
#define UGLIFY(U,B,S,E) template<typename ...T> ostream& operator<<(ostream&O,U<T...> a){ O<<B; int c=0; for(auto i:a)O<<(c++?S:"")<<i; return O<<E; } template<typename ...T> void _print(const char *s,U<T...> a,bool nxt_line = false,int idt = 0,int dim = Dim<U<T...>>::val,typename enable_if< (Dim<U<T...>>::val>1) >::type* = 0){ bool b = strlen(s); if(b) cerr<<s<<" =\n";if(nxt_line) cerr<<"\n"; cerr<<B; int c=0; string sep = S; for(int i=0;i<dim-1;++i)sep += "\n"; for(int i=0;i<idt+1;++i)sep += " "; for(auto i:a){ cerr<<(c++?sep:""); _print("",i,0,idt+1,dim-1); } cerr<<E; cerr<<(b?"\n":""); return; }
#ifdef ONLINE_JUDGE
#define print(arg...) 0
#else
#define print(arg...) _print_all(#arg,arg);
#endif
#define endl '\n'

template<typename T> struct Dim{ enum {val = 0}; }; DIM(vector); DIM(deque); DIM(set); DIM(multiset); DIM(unordered_set); template<typename S,typename T> struct Dim<map<S,T>>{ enum {val = 1 + Dim<T>::val}; }; template<typename S,typename T> struct Dim<unordered_map<S,T>>{ enum {val = 1 + Dim<T>::val}; }; template<typename S,typename T> ostream& operator<<(ostream&O,pair<S,T> a){ return O<<"("<<a.first<<", "<<a.second<<")"; } template<typename T> void _print(const char *s,T a,bool nxt_line = false,int idt = 0,int dim = Dim<T>::val,typename enable_if< (Dim<T>::val<=1) >::type* = 0){ bool b = strlen(s); if(b) cerr<<s<<" = "; cerr<<a<<(b?"\n":""); return; }
UGLIFY(vector,"[",", ","]"); UGLIFY(deque,"[",", ","]"); UGLIFY(set,"{",", ","}"); UGLIFY(multiset,"{",", ","}"); UGLIFY(unordered_set,"{",", ","}"); UGLIFY(map,"{",", ","}"); UGLIFY(unordered_map,"{",", ","}"); 
template<typename ...T> void _print_all(const char*s,T... a){ cerr<<s<<" = "; int c=0; ((cerr<<(c++?", ":""),_print("",a,true)),...); cerr<<"\n"; }

signed main(){
	IO;
	int n,m;
	cin>>n>>m;
	if(n==1||n==2){
		cout<<0;
		return 0;
	}
	vector<vector<pii>> e(n+1);
	int a,b,c;
	FOR(i,0,m){
		cin>>a>>b>>c;
		e[a].pb(b,c);
	}

	ll ans = 1e16,tmp = 0;
	FOR(i,2,n+1){
		print(i);
		vi dis(n+1,-1);
		set<pii>s;
		s.insert({0,1});
		s.insert({0,i});
		dis[1] = 0;
		dis[i] = 0;

		while(s.size()){
			pii u = *(s.begin());
			s.erase(s.begin());
			for(auto ee:e[u.S]){
				if(dis[ee.F] == -1){
					dis[ee.F] = u.F + ee.S;
					s.insert({dis[ee.F],ee.F});
				}
				else if(u.F + ee.S < dis[ee.F]){
					s.erase({dis[ee.F],ee.F});
					dis[ee.F] = u.F + ee.S;
					s.insert({dis[ee.F],ee.F});
				}
			}
			print(dis);
		}
		tmp = 0;
		FOR(i,1,n+1){
			tmp += dis[i];
		}
		ans = min(ans,tmp);
	}
	cout<<ans;
	return 0;
}