#include <cstdio> #include <vector> #include <set> #include <stack> #include <algorithm> #define REP(i,n) for(int i=0;i<(int)n;++i) #define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i) #define ALL(c) (c).begin(), (c).end() using namespace std; typedef int Weight; typedef vector<Weight> Array; typedef vector<Array> Matrix; const int M = 20; Weight best[1<<M][M]; int prev[1<<M][M]; void buildPath(int S, int i, vector<int> &path) { if (!S) return; buildPath(S^(1<<i), ::prev[S][i], path); path.push_back(i); } Weight shortestHamiltonPath(const Matrix &w, vector<int> &path) { int n=w.size(); int N = 1 << n; REP(S,N) REP(i,n) best[S][i] = 0; REP(S,N) REP(j,n) if (!(S&(1<<j))) { int score = 0; REP(i,n) if (S&(1<<i)) score+=w[i][j]; REP(i,n) if (best[S|(1<<j)][j] <= best[S][i] + score) { best[S|(1<<j)][j] = best[S][i] + score; ::prev[S|(1<<j)][j] = i; } } int t = max_element(best[N-1], best[N-1]+n) - best[N-1]; //path.clear(); buildPath(N-1, t, path); return best[N-1][t]; } int main(){ int N,M; scanf("%d%d",&N,&M); Matrix m(N); for(int i=0;i<N;i++)m[i].resize(N); for(;M--;){ int a,b,c; scanf("%d%d%d",&a,&b,&c); #ifdef ONLINE_JUDGE a--;b--; #endif m[a][b]=c; } vector<int> path; printf("%d\n",shortestHamiltonPath(m,path)); }