Problem Link : http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=1237
Solution Idea:
—————–
Light OJ: 1086 – Jogging Trails is a similar problem. The main idea behind this problem is Chinese Postman Problem.
For details about this theorem is described in book Competitive programming 3 by Steven Halim.
#include <bits/stdc++.h> #define pii pair <int,int> #define pll pair <long long,long long> #define sc scanf #define pf printf #define Pi 2*acos(0.0) #define ms(a,b) memset(a, b, sizeof(a)) #define pb(a) push_back(a) #define MP make_pair #define db double #define ll long long #define EPS 10E-10 #define ff first #define ss second #define sqr(x) (x)*(x) #define D(x) cout<<#x " = "<<(x)<<endl #define VI vector <int> #define DBG pf("Hi\n") #define MOD 1000000007 #define CIN ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0) #define SZ(a) (int)a.size() #define sf(a) scanf("%d",&a) #define sfl(a) scanf("%lld",&a) #define sff(a,b) scanf("%d %d",&a,&b) #define sffl(a,b) scanf("%lld %lld",&a,&b) #define sfff(a,b,c) scanf("%d %d %d",&a,&b,&c) #define sfffl(a,b,c) scanf("%lld %lld %lld",&a,&b,&c) #define stlloop(v) for(__typeof(v.begin()) it=v.begin();it!=v.end();it++) #define loop(i,n) for(int i=0;i<n;i++) #define loop1(i,n) for(int i=1;i<=n;i++) #define REP(i,a,b) for(int i=a;i<b;i++) #define RREP(i,a,b) for(int i=a;i>=b;i--) #define TEST_CASE(t) for(int z=1;z<=t;z++) #define PRINT_CASE printf("Case %d: ",z) #define LINE_PRINT_CASE printf("Case %d:\n",z) #define CASE_PRINT cout<<"Case "<<z<<": " #define all(a) a.begin(),a.end() #define intlim 2147483648 #define infinity (1<<28) #define ull unsigned long long #define gcd(a, b) __gcd(a, b) #define lcm(a, b) ((a)*((b)/gcd(a,b))) using namespace std; /*----------------------Graph Moves----------------*/ //const int fx[]={+1,-1,+0,+0}; //const int fy[]={+0,+0,+1,-1}; //const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1}; // Kings Move //const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1}; // Kings Move //const int fx[]={-2, -2, -1, -1, 1, 1, 2, 2}; // Knights Move //const int fy[]={-1, 1, -2, 2, -2, 2, -1, 1}; // Knights Move /*------------------------------------------------*/ /*-----------------------Bitmask------------------*/ int Set(int N,int pos) { return N=N | (1<<pos); } int reset(int N,int pos) { return N= N & ~(1<<pos); } bool check(int N,int pos) { return (bool)(N & (1<<pos)); } /*------------------------------------------------*/ ll g[16][16]; int degree[16]; ll dp[1<<16]; int n,m; void floyed_warshal() { for(int k=0; k<n; k++) for(int i=0; i<n; i++) for(int j=0; j<n; j++) { if(g[i][j]>g[i][k]+g[k][j]) g[i][j]=g[i][k]+g[k][j]; } } ll func(int mask) { if(mask==0) return 0; ll &ret=dp[mask]; if(ret!=-1) return ret; int pos=0; for(int i=0; i<n; i++) if(check(mask,i)) { pos=i; break; } ret=INT_MAX; for(int i=pos+1;i<n;i++) { if(check(mask,i)) { int temp_mask=mask; temp_mask=reset(temp_mask,pos); temp_mask=reset(temp_mask,i); ret=min(ret,g[pos][i]+func(temp_mask)); } } return ret; } int main() { // freopen("in.txt","r",stdin); // freopen("out.txt","w",stdout); int t; // sf(t); // TEST_CASE(t) while(sf(n) && n) { sf(m); // sff(n,m); ll ans=0; for(int i=0; i<=n; i++) for(int j=0; j<=n; j++) g[i][j]=INT_MAX; ms(degree,0); for(int i=0; i<m; i++) { ll a,b,c; sfffl(a,b,c); a--; b--; g[a][b]=min(g[a][b],c); g[b][a]=min(g[b][a],c); degree[a]++; degree[b]++; ans+=c; } floyed_warshal(); int mask=0; for(int i=0; i<n; i++) if(degree[i]%2) mask=Set(mask,i); // PRINT_CASE; ms(dp,-1); printf("%lld\n",ans+func(mask)); } return 0; }