Problem Link : http://www.lightoj.com/volume_showproblem.php?problem=1040
/* +-+ +-+ +-+ |R| |.| |S| +-+ +-+ +-+ */ #include <bits/stdc++.h> #define pii pair <int,int> #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 100007 #define MAX 10000 #define CIN ios_base::sync_with_stdio(0); cin.tie(0) #define SZ(a) (int)a.size() #define sf(a) scanf("%d",&a) #define sff(a,b) scanf("%d%d",&a,&b) #define sfff(a,b,c) scanf("%d%d%d",&a,&b,&c) #define loop(i,n) for(int i=0;i<n;i++) #define REP(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 all(a) a.begin(),a.end() #define intlim 2147483648 #define inf 1000000 #define ull unsigned long long using namespace std; struct data { int u,v,w; bool operator < (const data& p) const { return w<p.w; } data(int x,int y,int z) { u=x; v=y; w=z; } }; int par[MAX],test[MAX]; vector<data>edge; int n; int find_par(int n) { return par[n]= (par[n]==n)?n:find_par(par[n]); } int find_par_test(int n) { return test[n]= (test[n]==n)?n:find_par_test(test[n]); } int kruskal() { sort(all(edge)); int cost=0,cnt=0; loop(i,SZ(edge)) { int u=find_par(edge[i].u); int v=find_par(edge[i].v); if(u!=v) { par[u]=v; cost+=edge[i].w; cnt++; if(cnt==n-1) return cost; } } } void allclear() { loop(i,n+2) { test[i]=i; par[i]=i; } edge.clear(); } int main() { ///freopen("in.txt","r",stdin); ///freopen("out.txt","w",stdout); int t,c; sf(t); TEST_CASE(t) { sf(n); allclear(); int total_cost=0; loop(i,n) loop(j,n) { c=0; sf(c); if(c) { total_cost+=c; edge.pb(data(i,j,c)); int a=find_par_test(i); int b=find_par_test(j); if(a!=b) { test[a]=b; } } } int cnt=0; loop(i,n) if(test[i]==i) cnt++; PRINT_CASE; if(cnt>1) { cout<<-1<<endl; continue; } else { int temp=kruskal(); cout<<total_cost-temp<<endl; } } return 0; }