无向图中国邮路(小数据版)

http://ac.jobdu.com/problem.php?pid=1430

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <queue>
#include <algorithm>
#include <vector>
#include <cstring>
#include <stack>
#include <cctype>
#include <utility>   
#include <map>
#include <string>  
#include <climits> 
#include <set>
#include <string>    
#include <sstream>
#include <utility>   
#include <ctime>
#include <bitset>
#include <iomanip>
//#pragma comment(linker, "/STACK:102400000,102400000")

using std::priority_queue;
using std::vector;
using std::swap;
using std::stack;
using std::sort;
using std::max;
using std::min;
using std::pair;
using std::map;
using std::string;
using std::cin;
using std::cout;
using std::set;
using std::queue;
using std::string;
using std::stringstream;
using std::make_pair;
using std::getline;
using std::greater;
using std::endl;
using std::multimap;
using std::deque;
using std::unique;
using std::lower_bound;
using std::random_shuffle;
using std::bitset;
using std::upper_bound;
using std::multiset;
using std::ios;
using std::make_heap;
using std::push_heap;
using std::pop_heap;

typedef long long LL;
typedef unsigned long long ULL;
typedef unsigned UN;
typedef pair<ULL, ULL> PAIR;
typedef multimap<int, int> MMAP;
typedef long double LF;

const int MAXN(25);
const int MAXM(310);
const int MAXE(310);
const int MAXK(6);
const int HSIZE(131313);
const int SIGMA_SIZE(26);
const int MAXH(18);
const int INFI((INT_MAX-1) >> 1);
const ULL BASE(31);
const LL LIM(1e13);
const int INV(-10000);
const int MOD(1000000007);
const double EPS(1e-7);
const LF PI(acos(-1.0));

template<typename T> inline void checkmax(T &a, T b){if(b > a) a = b;}
template<typename T> inline void checkmin(T &a, T b){if(b < a) a = b;}
template<typename T> inline T ABS(const T &a){return a < 0? -a: a;}

int deg[MAXN];
LL dis[MAXN][MAXN];
LL dp[1 << 20];
LL solve(int n)
{
	int can = 0;
	for(int i = 0; i < n; ++i)
		if(deg[i]&1)
			can |= (1 << i);
	if(can == 0) return 0;
	for(int i = 1; i <= can; ++i)
	{
		dp[i] = LIM;
		if((can|i) != can) continue;
		int mi;
		for(int j = 0; j < n; ++j)
			if(((i >> j)&1) == 1)
			{
				mi = j;
				break;
			}
		int ti = i^(1 << mi);
		for(int j = mi+1; j < n; ++j)
			if(((i >> j)&1) == 1)
				checkmin(dp[i], dp[ti^(1 << j)]+dis[mi][j]);
	}
	LL ret = LIM;
	for(int i = 0; i < n; ++i)
		if(can&(1 << i))
			for(int j = i+1; j < n; ++j)
				if(can&(1 << j))
					checkmin(ret, dp[can^(1 << i)^(1 << j)]);
	return ret;
}

int main()
{
	int TC;
	scanf("%d", &TC);
	while(TC--)
	{
		LL ans = 0;
		int n, m;
		scanf("%d%d", &n, &m);
		for(int i = 0; i < n; ++i)
		{
			deg[i] = 0;
			for(int j = i+1; j < n; ++j)
				dis[i][j] = dis[j][i] = LIM;
		}
		int u, v, w;
		for(int i = 0; i < m; ++i)
		{
			scanf("%d%d%d", &u, &v, &w);
			--u, --v;
			++deg[u], ++deg[v];
			checkmin(dis[u][v], (LL)w);
			checkmin(dis[v][u], (LL)w);
			ans += w;
		}
		for(int i = 0; i < n; ++i)
			for(int j = 0; j < n; ++j)
				for(int k = 0; k < n; ++k)
					checkmin(dis[j][k], dis[j][i]+dis[i][k]);
		bool flag(true);
		for(int i = 0; i < n && flag; ++i)
			for(int j = i+1; j < n && flag; ++j)
				if(dis[i][j] == LIM)
					flag = false;
		if(flag) ans += solve(n);
		else ans = -1;
		printf("%lld\n", ans);
	}
	return 0;
}