挺有意思的hhh有个坑
1 #include<cstdio> 2 #include<cstring> 3 #include<cmath> 4 #include<ctime> 5 #include<iostream> 6 #include<algorithm> 7 #include<queue> 8 #include<set> 9 #define inf (1e10) 10 #define l(a) ((a)<<1) 11 #define r(a) ((a)<<1|1) 12 #define b(a) (1<<(a)) 13 #define rep(i,a,b) for(int i=a;i<=(b);i++) 14 #define clr(a) memset(a,0,sizeof(a)) 15 typedef long long ll; 16 typedef unsigned long long ull; 17 using namespace std; 18 int readint(){ 19 int t=0,f=1;char c=getchar(); 20 while(!isdigit(c)){ 21 if(c=='-') f=-1; 22 c=getchar(); 23 } 24 while(isdigit(c)){ 25 t=(t<<3)+(t<<1)+c-'0'; 26 c=getchar(); 27 } 28 return t*f; 29 } 30 const int maxn=209; 31 int n,x[maxn],y[maxn]; 32 double d[maxn][maxn],w[maxn]; 33 double dis(int a,int b){ 34 return sqrt((x[a]-x[b])*(x[a]-x[b])+(y[a]-y[b])*(y[a]-y[b])); 35 } 36 int main(){ 37 //freopen("#input.txt","r",stdin); 38 //freopen("#output.txt","w",stdout); 39 n=readint(); 40 rep(i,1,n){ 41 x[i]=readint();y[i]=readint(); 42 } 43 rep(i,1,n) 44 rep(j,1,n){ 45 char c=getchar(); 46 while(c!='0'&&c!='1') c=getchar(); 47 if(c=='0'&&i!=j) d[i][j]=inf; 48 else d[i][j]=dis(i,j); 49 } 50 rep(k,1,n) 51 rep(i,1,n) 52 rep(j,1,n) d[i][j]=min(d[i][j],d[i][k]+d[k][j]); 53 rep(i,1,n) 54 rep(j,1,n) if(d[i][j]!=inf) w[i]=max(w[i],d[i][j]); 55 double ans=inf; 56 rep(i,1,n) 57 rep(j,1,n) if(d[i][j]==inf) ans=min(ans,w[i]+w[j]+dis(i,j)); 58 rep(i,1,n) ans=max(ans,w[i]); 59 printf("%.6lf ",ans); 60 //fclose(stdin); 61 //fclose(stdout); 62 return 0; 63 }