我想通过从csv读取来创建给定邻接矩阵的无向加权图。我可以从csv中读取它，但我不知道如何绘制它的图形。有人可以帮忙吗？这是用于读取文件的代码。
int main(){
ifstream ip("map.csv");
if(!ip.is_open()) std::cout << "ERROR: File Open" << '\n';
string first;
string weight;
while(ip.good()){
getline(ip,first);
getline(ip,weight);
std::cout << "First: "<<first <<'\n';
std::cout << "Weight: "<<weight<< '\n';
std::cout << "-------------------" << '\n';
}
ip.close();
}
这是用图表实现它的代码。
class Graph {
private:
bool** adjacencyMatrix;
int vertexCount;
public:
Graph(int vertexCount) {
ip->vertexCount = vertexCount;
adjacencyMatrix = new bool*[vertexCount];
for (int i = 0; i < vertexCount; i++) {
adjacencyMatrix[i] = new bool[vertexCount];
for (int j = 0; j < vertexCount; j++)
adjacencyMatrix[i][j] = false;
}
}
void addEdge(int i, int j) {
if (i >= 0 && i < vertexCount && j > 0 && j < vertexCount) {
adjacencyMatrix[i][j] = true;
adjacencyMatrix[j][i] = true;
}
}
void removeEdge(int i, int j) {
if (i >= 0 && i < vertexCount && j > 0 && j < vertexCount) {
adjacencyMatrix[i][j] = false;
adjacencyMatrix[j][i] = false;
}
}
bool isEdge(int i, int j) {
if (i >= 0 && i < vertexCount && j > 0 && j < vertexCount)
return adjacencyMatrix[i][j];
else
return false;
}
~Graph() {
for (int i = 0; i < vertexCount; i++)
delete[] adjacencyMatrix[i];
delete[] adjacencyMatrix;
}
};
这就是我的文件的样子。
C1,C2,C3,C4,C5,C6,C7,C8,C9,C10,C11
C1,-1,20,-1,40,-1,-1,-1,-1,-1,-1,-1
C2,20,-1,-1,-1,80,-1,-1,-1,-1,-1,-1
C3,-1,-1,-1,-1,60,-1,-1,-1,-1,-1,-1
C4,40,-1,-1,-1,-1,200,-1,-1,-1,-1,-1
C5,-1,80,60,-1,-1,-1,100,-1,43,-1,-1
C6,-1,-1,-1,200,-1,-1,33,-1,-1,-1,-1
C7,-1,-1,-1,-1,100,33,-1,-1,-1,-1,-1
C8,-1,-1,-1,-1,-1,-1,-1,-1,4,-1,55
C9,-1,-1,-1,-1,43,-1,-1,4,-1,-1,-1
C10,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,32
C11,-1,-1,-1,-1,-1,-1,-1,55,-1,32,-1
我不知道如何使用读取文件的输出来实现图形。帮助将受到高度赞赏。
答案 0 :(得分：1)
这是我的建议。
首先，我决定应用@Scheff修改（或多或少），vector vector作为邻接矩阵。我认为使代码更清晰，而不是使用row * vertexCount + column类型访问。
#include <unordered_map>
#include <vector>
#include <string>
class Graph {
private:
typedef std::vector < std::vector<int> > tAdjacencyMatrix;
private:
tAdjacencyMatrix adj;
int vertexCount;
public:
Graph(int vertexCount) {
this->vertexCount = vertexCount;
for (int i = 0; i < vertexCount; i++) {
std::vector<int> v;
for (int j = 0; j < vertexCount; j++)
v.push_back(0);
adj.push_back(v);
}
}
void addEdge(int i, int j, int value) {
if (i >= 0 && i < vertexCount && j > 0 && j < vertexCount) {
adj[i][j] = value;
adj[j][i] = value;
}
}
void removeEdge(int i, int j) {
if (i >= 0 && i < vertexCount && j > 0 && j < vertexCount) {
adj[i][j] = 0;
adj[j][i] = 0;
}
}
bool isEdge(int i, int j) const {
if (i >= 0 && i < vertexCount && j > 0 && j < vertexCount)
return adj[i][j]; // 0 interpreted as false
}
std::string toString() const{
std::string ret = "";
for (int i = 0; i < vertexCount; i++) {
ret += "V1: ";
for (int j = 0; j < vertexCount; j++){
ret += std::to_string(adj[i][j]);
if (j != vertexCount - 1) ret += ", ";
}
ret += "\n";
}
return ret;
}
};
我添加了一个toString方法来探测它是否正常工作。
注意：您可以使用adj.size()代替vertexCount。
有了这个，我的主要看起来像：
int main(){
ifstream ip("map.csv");
if (!ip.is_open()) std::cout << "ERROR: File Open" << '\n';
string line;
getline(ip, line);
vector<string> tokens = splitString(line, ',');
int vertexCount = tokens.size();
Graph g(vertexCount);
int v = 1;
while (ip.good()){
getline(ip, line);
tokens = splitString(line, ',');
for (int i = 1; i < tokens.size(); ++i){ // Note that starts in 1, avoiding "Cx" first element
if (tokens[i].compare("-1") != 0){
g.addEdge(v, i, atoi(tokens[i].c_str()));
}
}
++v;
}
ip.close();
cout << g.toString() << endl;
return 0;
}
拆分字符串功能：
std::vector<string> splitString(const string &s, char delimiter){
istringstream iis(s);
vector<string> tokens;
string aux = "";
char c;
while (iis.good()){
c = iis.get();
if (c == delimiter){
tokens.push_back(aux);
aux.clear();
}
else{
aux.insert(aux.end(), c);
}
}
tokens.push_back(aux); // Insert the last one (it has no ',' at the end)
return tokens;
}
Note2 ：分割功能肯定会更好，但我觉得这个更容易理解