TCO14 2C l2:cliquegraph,graph theory, clique

Title: http://community.topcoder.com/stat?c=problem_statement&pm=13251&rd=16017

References: Http://apps.topcoder.com/wiki/display/tc/TCO+2014+Round+2C

Assume that each edge is calculated first, the adjacency matrix is used to represent the graph, and then the BFS or Floyd-warshall algorithm is used to calculate the distance. The time complexity is O (n^3), which times out. According to the title of the tip know to use the nature of clique graph to do. The basic idea is to treat a clique as a whole in BFS. Once you visit a point in the clique, the distance from all points in the clique is available. Algorithmic descriptive narratives such as the following

For each source vertex s:
Mark all vertices and all cliques as unvisited
Start BFS from S
When processing a vertex v during the BFS:
For each unvisited clique C that contains V:
Mark C as visited
Use edges on C to discover new vertices

Code:

#include <algorithm> #include <functional> #include <numeric> #include <utility> #include < iostream> #include <sstream> #include <iomanip> #include <bitset> #include <string> #include <vector> #include <stack> #include <deque> #include <queue> #include <set> #include < map> #include <cstdio> #include <cstdlib> #include <cctype> #include <cmath> #include < cstring> #include <ctime> #include <climits>using namespace std; #define CHECKTIME () printf ("%.2lf\n", ( Double) (Clock ()/clocks_per_sec) typedef pair<int, int> pii;typedef long Long llong;typedef Pair<llong, Llong > PLL, #define MKP make_pair/*************** program Begin **********************/bool Visited_vertex[5001];bool Visited_clique[5001];class cliquegraph {public:long long calcsum (int N, vector <int> V, vector <int> sizes) {L Ong Long res = 0;vector <int> S (sizes.size () + 1); S[0] = 0;for (int i= 0; I < sizes.size (); i++) {s[i + 1] + = S[i] + sizes[i];}  Vector <vector<int>> cliques (sizes.size ());//clique I include the point vector <vector<int>> vcliques (N); Cliquesfor including point V (int i = 0; i < sizes.size (); i++) {for (int j = S[i]; J < S[i + 1]; j + +) {Cliques[i].push_back (v [j]); vcliques[V[j]].push_back (i);}} for (int src = 0; src < N; src++) {vector <int> D (N, 123456789);D [src] = 0;memset (Visited_vertex, 0, sizeof (visit Ed_vertex)); memset (visited_clique, 0, sizeof (visited_clique)); queue <int> Q; Q.push (SRC); visited_vertex[src] = True;while (! Q.empty ()) {int v = q.front (); Q.pop ();//update all the points in the cliques that include V for (int i = 0; i < vcliques[v].size (); i++) {int c = vcliques[v][i];//cliquesif including V (v Isited_clique[c]) {continue;} VISITED_CLIQUE[C] = true;for (int j = 0; J < Cliques[c].size (); j + +) {int u = cliques[c][j];//clique C Z for Point if (visite D_vertex[u]) {continue;} Visited_vertex[u] = True;d[u] = D[v] + 1; Q.push (U);}} for (int i = 0; i < N; i++) {res + = D[i];}} Return res/2;};};/ Program End ************************/

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TCO14 2C l2:cliquegraph,graph theory, clique