dimacs2metis

.gitignore

@@ -0,0 +1,3 @@
+dimacs2txt
+dimacs2metis
+test_dimacs

dimacs2metis.cpp

@@ -0,0 +1,192 @@
+// =====================================================================================
+//
+//       Filename:  dimacs2metis.cpp
+//
+//    Description:  convert dimacs graph to metis format
+//
+//        Version:  1.0
+//        Created:  2017年 12月 28日 星期四 07:03:07 -00
+//       Revision:  none
+//       Compiler:  g++
+//
+//         Author:  Jinkun Lin, jkunlin@gmail.com
+//   Organization:  School of EECS, Peking University
+//
+// =====================================================================================
+#include <iostream>
+#include <vector>
+#include <fstream>
+using namespace std;
+
+int vertex_count = 0, edge_count = 0;
+vector<vector<int>> adjacency_list;
+vector<int> vertex_weight;
+// read graph file into adjacency_list
+void fast_read(string file_name) {/*{{{*/
+	ifstream in_file(file_name);
+	if (!in_file) {
+		cout << "in_file error" << endl;
+		exit(1);
+	}
+	in_file.seekg (0, in_file.end);
+	size_t file_len = in_file.tellg();
+	in_file.seekg (0, in_file.beg);
+	char *data = new char [file_len];
+
+	in_file.read(data, file_len);
+	in_file.close();
+
+	//skip comments
+	char *pos = data;
+	while (*pos == '%') {
+		while(*(pos++) != '\n');
+	}
+
+	//read vertex_count
+	while (*pos < '0' || *pos > '9') {
+		++pos;
+	}
+	while (*pos != ' ') {
+		vertex_count = vertex_count * 10 +  *pos - '0';
+		++pos;
+	}
+	//read edge_count
+	while (*pos < '0' || *pos > '9') {
+		++pos;
+	}
+	while (*pos >= '0' && *pos <= '9') {
+		edge_count = edge_count * 10 +  *pos - '0';
+		++pos;
+	}
+
+	//read vertex_weight
+	vertex_weight.resize(vertex_count + 1);
+	int v,w;
+	for(vector<vector<int>>::size_type i=1; i<vertex_weight.size(); ++i){
+		v = w = 0;
+		//read vertex
+		while (*pos < '0' || *pos > '9') {
+			++pos;
+		}
+		while (*pos != ' ') {
+			v = v * 10 +  *pos - '0';
+			++pos;
+		}
+		//read weight
+		while (*pos < '0' || *pos > '9') {
+			++pos;
+		}
+		while (*pos >= '0' && *pos <= '9') {
+			w = w * 10 +  *pos - '0';
+			++pos;
+		}
+		vertex_weight[v]=w;
+	}
+
+	//read adjacency_list
+	adjacency_list.resize(vertex_count + 1);
+
+	vector<int> vertex_degree(vertex_count + 1, 0);
+	char *stash_pos = pos;
+	int v1, v2;
+	for (int i = 0; i < edge_count; ++i) {
+		v1 = v2 = 0;
+		//read v1
+		while (*pos < '0' || *pos > '9') {
+			++pos;
+		}
+		while (*pos != ' ') {
+			v1 = v1 * 10 +  *pos - '0';
+			++pos;
+		}
+		//read v2
+		while (*pos < '0' || *pos > '9') {
+			++pos;
+		}
+		while (*pos >= '0' && *pos <= '9') {
+			v2 = v2 * 10 +  *pos - '0';
+			++pos;
+		}
+		vertex_degree[v1]++;
+		vertex_degree[v2]++;
+	}
+	for (size_t v = 1; v < adjacency_list.size(); ++v) {
+		adjacency_list[v].reserve(vertex_degree[v]);
+	}
+	pos = stash_pos;
+	for (int i = 0; i < edge_count; ++i) {
+		v1 = v2 = 0;
+		//read v1
+		while (*pos < '0' || *pos > '9') {
+			++pos;
+		}
+		while (*pos != ' ') {
+			v1 = v1 * 10 +  *pos - '0';
+			++pos;
+		}
+		//read weight
+		while (*pos < '0' || *pos > '9') {
+			++pos;
+		}
+		while (*pos >= '0' && *pos <= '9') {
+			v2 = v2 * 10 +  *pos - '0';
+			++pos;
+		}
+		adjacency_list[v1].push_back(v2);
+		adjacency_list[v2].push_back(v1);
+	}
+	delete[] data;
+}/*}}}*/
+
+void convert(string graph_name) {
+	ofstream out_graph(graph_name);
+	if (!out_graph) {
+		std::cout << "outfile error" << std::endl;
+		abort();
+	}
+	out_graph << vertex_count << ' ' << edge_count << endl;
+	for (size_t v = 1; v < adjacency_list.size(); ++v) {
+		out_graph << adjacency_list[v][0];
+		for (size_t i = 1; i < adjacency_list[v].size(); ++i) {
+			int u = adjacency_list[v][i];	
+			out_graph << ' ' << u;
+		}
+		out_graph << std::endl;
+	}
+
+	ofstream out_weight(graph_name + ".weights");
+	if (!out_weight) {
+		std::cout << "weights file error" << std::endl;
+		abort();
+	}
+	
+	// offset = -1
+	for (int v = 0; v < vertex_count; ++v) {
+		out_weight << v << ' ' << vertex_weight[v + 1] << std::endl;
+	}
+
+	out_graph.close();
+	out_weight.close();
+}
+int main(int argc, char const *argv[]) {
+	if (argc != 2) {
+		std::cout << "usage" << std::endl;
+		return 1;
+	}
+
+	string in_filename = argv[1];
+	fast_read(in_filename);
+	
+	string graph_name;
+	size_t begin_index = 0;
+	if ((begin_index = in_filename.find_last_of('/')) != string::npos) {
+		graph_name = in_filename.substr(begin_index + 1, in_filename.size() - 5 - begin_index - 1);
+	}
+	else {
+		graph_name = in_filename.substr(0, in_filename.size() -5);
+	}
+	graph_name += ".graph";
+
+	convert(graph_name);
+	return 0;
+}

test_dimacs.cpp

@@ -142,6 +142,10 @@ void fast_read(string file_name) {/*{{{*/
 void test() {
 	for (size_t v = 1; v < adjacency_list.size(); ++v) {
 		std::sort(adjacency_list[v].begin(), adjacency_list[v].end());
+		if (adjacency_list[v].empty()) {
+			std::cout << "acnode" << std::endl;
+			abort();
+		}
 		for (size_t i = 0; i < adjacency_list[v].size(); ++i) {
 			if (adjacency_list[v][i] == (int)v) {
 				std::cout << "loop" << std::endl;
@@ -153,6 +157,7 @@ void test() {
 			}
 		}
 	}
+	std::cout << "pass" << std::endl;
 }
 
 int main(int argc, char const *argv[]) {