【HDOJ】1706 The diameter of graph

这么个简单的题目居然没有人题解。floyd中计算数目，同时注意重边。

 /* 1706 */
 #include <iostream>
 #include <string>
 #include <map>
 #include <queue>
 #include <set>
 #include <stack>
 #include <vector>
 #include <deque>
 #include <algorithm>
 #include <cstdio>
 #include <cmath>
 #include <ctime>
 #include <cstring>
 #include <climits>
 #include <cctype>
 #include <cassert>
 #include <functional>
 #include <iterator>
 #include <iomanip>
 using namespace std;
 //#pragma comment(linker,"/STACK:102400000,1024000")

 #define sti                set<int>
 #define stpii            set<pair<int, int> >
 #define mpii            map<int,int>
 #define vi                vector<int>
 #define pii                pair<int,int>
 #define vpii            vector<pair<int,int> >
 #define rep(i, a, n)     for (int i=a;i<n;++i)
 #define per(i, a, n)     for (int i=n-1;i>=a;--i)
 #define clr                clear
 #define pb                 push_back
 #define mp                 make_pair
 #define fir                first
 #define sec                second
 #define all(x)             (x).begin(),(x).end()
 #define SZ(x)             ((int)(x).size())
 #define lson            l, mid, rt<<1
 #define rson            mid+1, r, rt<<1|1

 const int INF = 0x3f3f3f3f;
 const int maxn = ;
 int dis[maxn][maxn];
 int M[maxn][maxn];
 int cnt[maxn][maxn];
 int n, m;

 void floyd() {
     rep(k, , n+) {
         rep(i, , n+) {
             if (M[i][k]>=INF || i==k)
                 continue;
             rep(j, , n+) {
                 if (M[k][j]>=INF || k==j || i==j)
                     continue;
                 if (M[i][j] > M[i][k]+M[k][j]) {
                     M[i][j] = M[i][k] + M[k][j];
                     cnt[i][j] = cnt[i][k] * cnt[k][j];
                 } else if (M[i][j] == M[i][k]+M[k][j]) {
                     cnt[i][j] += cnt[i][k] * cnt[k][j];
                 }
             }
         }
     }
 }

 int main() {
     ios::sync_with_stdio(false);
     #ifndef ONLINE_JUDGE
         freopen("data.in", "r", stdin);
         freopen("data.out", "w", stdout);
     #endif

     int u, v, w;
     int mx;
     int ans;

     while (scanf("%d %d", &n, &m)!=EOF) {
         memset(M, 0x3f, sizeof(M));
         memset(cnt, , sizeof(cnt));
         rep(i, , m) {
             scanf("%d %d %d", &u, &v, &w);
             if (u == v)
                 continue;
             if (M[u][v] > w) {
                 M[u][v] = M[v][u] = w;
                 cnt[u][v] = cnt[v][u] = ;
             } else if (M[u][v] == w) {
                 ++cnt[u][v];
                 ++cnt[v][u];
             }
         }
         floyd();
         ans = ;
         mx = -;
         rep(i, , n+) {
             rep(j, , i) {
                 if (M[i][j]==INF || i==j)
                     continue;
                 if (mx < M[i][j]) {
                     mx = M[i][j];
                     ans = cnt[i][j];
                 } else if (mx == M[i][j]) {
                     ans += cnt[i][j];
                 }
             }
         }
         printf("%d %d\n", mx, ans);
     }

     #ifndef ONLINE_JUDGE
         printf("time = %d.\n", (int)clock());
     #endif

     return ;
 }