HDU 3001 Travelling(状态压缩DP)

#include <iostream>
#include <cstdio>
#include <string.h>
#include <algorithm>
#include <cmath>
#include <vector>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <map>

#define max(x,y) ((x)>(y)?(x):(y))
#define min(x,y) ((x)<(y)?(x):(y))
#define abs(x) ((x)>=0?(x):-(x))
#define i64 long long
#define u32 unsigned int
#define u64 unsigned long long
#define clr(x,y) memset(x,y,sizeof(x))
#define CLR(x) x.clear()
#define ph(x) push(x)
#define pb(x) push_back(x)
#define Len(x) x.length()
#define SZ(x) x.size()
#define PI acos(-1.0)
#define sqr(x) ((x)*(x))
#define MP(x,y) make_pair(x,y)
#define EPS 1e-5

#define FOR0(i,x) for(i=0;i<x;i++)
#define FOR1(i,x) for(i=1;i<=x;i++)
#define FOR(i,a,b) for(i=a;i<=b;i++)
using namespace std;

void RD(int &x){scanf("%d",&x);}
void RD(i64 &x){scanf("%I64d",&x);}
void RD(u32 &x){scanf("%u",&x);}
void RD(double &x){scanf("%lf",&x);}
void RD(int &x,int &y){scanf("%d%d",&x,&y);}
void RD(i64 &x,i64 &y){scanf("%I64d%I64d",&x,&y);}
void RD(u32 &x,u32 &y){scanf("%u%u",&x,&y);}
void RD(double &x,double &y){scanf("%lf%lf",&x,&y);}
void RD(int &x,int &y,int &z){scanf("%d%d%d",&x,&y,&z);}
void RD(int &x,int &y,int &z,int &t){scanf("%d%d%d%d",&x,&y,&z,&t);}
void RD(i64 &x,i64 &y,i64 &z){scanf("%I64d%I64d%I64d",&x,&y,&z);}
void RD(u32 &x,u32 &y,u32 &z){scanf("%u%u%u",&x,&y,&z);}
void RD(double &x,double &y,double &z){scanf("%lf%lf%lf",&x,&y,&z);}
void RD(char &x){x=getchar();}
void RD(char *s){scanf("%s",s);}
void RD(string &s){cin>>s;}

void PR(int x) {printf("%d\n",x);}
void PR(i64 x) {printf("%I64d\n",x);}
void PR(u32 x) {printf("%u\n",x);}
void PR(u64 x) {printf("%I64u\n",x);}
void PR(double x) {printf("%.6lf\n",x);}
void PR(char x) {printf("%c\n",x);}
void PR(char *x) {printf("%s\n",x);}
void PR(string x) {cout<<x<<endl;}

const int mod=1000000009;
const int INF=1000000000;
const int N=200005;

int n,m;
int a[15][15];
int f[60000][10];
int p[15];

void init()
{
int i;
p[0]=1;
for(i=1;i<=10;i++) p[i]=3*p[i-1];
}

int getBit(int x,int t)
{
return x%p[t+1]/p[t];
}

int get()
{
int x=0;
char c=getchar();
while(!isdigit(c))
{
c=getchar();
}
while(isdigit(c))
{
x=x*10+c-'0';
c=getchar();
}
return x;
}

int OK(int x)
{
int i;
FOR0(i,n) if(!getBit(x,i)) return 0;
return 1;
}

int main()
{
init();
while(scanf("%d%d",&n,&m)!=-1)
{
int i,j,k;
FOR0(i,n) FOR0(j,n) a[i][j]=INF;
while(m--)
{
int u,v;
i64 w;
u=get()-1;
v=get()-1;
w=get();
if(a[u][v]>w) a[u][v]=a[v][u]=w;
}
int L=p
,x,y,st;
FOR0(i,L) FOR0(j,n) f[i][j]=INF;
FOR0(i,n) f[p[i]][i]=0;
for(i=1;i<L;i++) FOR0(j,n) FOR0(k,n) if(k!=j&&a[j][k]<INF)
{
x=getBit(i,k);
if(x==2) continue;
if(f[i+p[k]][k]>f[i][j]+a[j][k]) f[i+p[k]][k]=f[i][j]+a[j][k];
}
int ans=INF;
FOR0(i,L) if(OK(i)) FOR0(j,n) ans=min(ans,f[i][j]);
if(ans==INF) ans=-1;
PR(ans);
}
return 0;
}