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#include #include #include using namespace std;const int MAX = 205;int dep, n, map[MAX][MAX];int dfs(int u, int v){ int max1, max2, path_max; max1 = max2 = path_max = 0; for(int i = 1;i <= n;i ++){ if(map[i][u] && i != v){ int z = dfs(i, u); if(path_max < z) path_max = z; if(max1 < dep){ max2 = max1; max1 = dep; } else if(max2 < dep) max2 = dep; } } if(path_max < max1 + max2) path_max = max2 + max1; dep = max1 + 1; return path_max;}int main(int argc, char const *argv[]){ int u, v; //freopen("in.c", "r", stdin); while(~scanf("%d", &n)){ memset(map, 0, sizeof(map)); for(int i = 0; i < n - 1;i ++){ scanf("%d%d", &u, &v); map[u][v] = map[v][u] = 1; } int ans = -1; for(int i = 1;i <= n;i ++){ for(int j = 1;j <= n;j ++){ if(map[i][j]){ int a = dfs(i, j); int b = dfs(j, i); ans = max(ans, a*b); } } } printf("%d\n", ans); } return 0;}
转载于:https://www.cnblogs.com/wangzhili/p/3950311.html