#include <iostream> #include <cstdio> #include <vector> #include <algorithm> using namespace std; const int MX = 404; int T[MX][MX]; void go() { int n; cin>>n; string s; for (int i =0; i<n; i++) { cin>>s; for (int j=0; j<n; j++) if (s[j] == '1') T[i][j]=1; else T[i][j] = (i == j ? 0 : 1000); } int res = 0; for (int k=0; k<n; k++) for (int i=0; i<n; i++) for (int j=0; j<n; j++) { T[i][j] = min(T[i][j], T[i][k] + T[k][j]); if (i!=j)res = max(res, T[i][j]); } for (int i =0; i<n; i++) for (int j=0; j<n; j++) { int a = 0, b = 0; for (int k =0; k<n; k++) { int c = min(T[k][i], T[k][j]); if (c > b) { if (c > a) { b = a; a = c; } else { b = c; } } } res = min(res, a + b); } cout << res << endl; } int main() { int t; cin>>t; while(t--) { go(); } return 0; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 | #include <iostream> #include <cstdio> #include <vector> #include <algorithm> using namespace std; const int MX = 404; int T[MX][MX]; void go() { int n; cin>>n; string s; for (int i =0; i<n; i++) { cin>>s; for (int j=0; j<n; j++) if (s[j] == '1') T[i][j]=1; else T[i][j] = (i == j ? 0 : 1000); } int res = 0; for (int k=0; k<n; k++) for (int i=0; i<n; i++) for (int j=0; j<n; j++) { T[i][j] = min(T[i][j], T[i][k] + T[k][j]); if (i!=j)res = max(res, T[i][j]); } for (int i =0; i<n; i++) for (int j=0; j<n; j++) { int a = 0, b = 0; for (int k =0; k<n; k++) { int c = min(T[k][i], T[k][j]); if (c > b) { if (c > a) { b = a; a = c; } else { b = c; } } } res = min(res, a + b); } cout << res << endl; } int main() { int t; cin>>t; while(t--) { go(); } return 0; } |