forked from TheAlgorithms/Java
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathMatrixGraphs.java
More file actions
147 lines (125 loc) · 4.45 KB
/
MatrixGraphs.java
File metadata and controls
147 lines (125 loc) · 4.45 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
package DataStructures.Graphs;
public class MatrixGraphs {
public static void main(String args[]) {
AdjacencyMatrixGraph graph = new AdjacencyMatrixGraph(10);
graph.addEdge(1, 2);
graph.addEdge(1, 5);
graph.addEdge(2, 5);
graph.addEdge(1, 2);
graph.addEdge(2, 3);
graph.addEdge(3, 4);
graph.addEdge(4, 1);
graph.addEdge(2, 3);
System.out.println(graph);
}
}
class AdjacencyMatrixGraph {
private int _numberOfVertices;
private int _numberOfEdges;
private int[][] _adjacency;
static final int EDGE_EXIST = 1;
static final int EDGE_NONE = 0;
public AdjacencyMatrixGraph(int givenNumberOfVertices) {
this.setNumberOfVertices(givenNumberOfVertices);
this.setNumberOfEdges(0);
this.setAdjacency(new int[givenNumberOfVertices][givenNumberOfVertices]);
for (int i = 0; i < givenNumberOfVertices; i++) {
for (int j = 0; j < givenNumberOfVertices; j++) {
this.adjacency()[i][j] = AdjacencyMatrixGraph.EDGE_NONE;
}
}
}
private void setNumberOfVertices(int newNumberOfVertices) {
this._numberOfVertices = newNumberOfVertices;
}
public int numberOfVertices() {
return this._numberOfVertices;
}
private void setNumberOfEdges(int newNumberOfEdges) {
this._numberOfEdges = newNumberOfEdges;
}
public int numberOfEdges() {
return this._numberOfEdges;
}
private void setAdjacency(int[][] newAdjacency) {
this._adjacency = newAdjacency;
}
private int[][] adjacency() {
return this._adjacency;
}
private boolean adjacencyOfEdgeDoesExist
984B
(int from, int to) {
return (this.adjacency()[from][to] != AdjacencyMatrixGraph.EDGE_NONE);
}
public boolean vertexDoesExist(int aVertex) {
if (aVertex >= 0 && aVertex < this.numberOfVertices()) {
return true;
} else {
return false;
}
}
public boolean edgeDoesExist(int from, int to) {
if (this.vertexDoesExist(from) && this.vertexDoesExist(to)) {
return (this.adjacencyOfEdgeDoesExist(from, to));
}
return false;
}
/**
* This method adds an edge to the graph between two specified
* vertices
*
* @param from the data of the vertex the edge is from
* @param to the data of the vertex the edge is going to
* @return returns true if the edge did not exist, return false if it already did
*/
public boolean addEdge(int from, int to) {
if (this.vertexDoesExist(from) && this.vertexDoesExist(to)) {
if (!this.adjacencyOfEdgeDoesExist(from, to)) {
this.adjacency()[from][to] = AdjacencyMatrixGraph.EDGE_EXIST;
this.adjacency()[to][from] = AdjacencyMatrixGraph.EDGE_EXIST;
this.setNumberOfEdges(this.numberOfEdges() + 1);
return true;
}
}
return false;
}
/**
* this method removes an edge from the graph between two specified
* vertices
*
* @param from the data of the vertex the edge is from
* @param to the data of the vertex the edge is going to
* @return returns false if the edge doesn't exist, returns true if the edge exists and is removed
*/
public boolean removeEdge(int from, int to) {
if (!this.vertexDoesExist(from) || !this.vertexDoesExist(to)) {
if (this.adjacencyOfEdgeDoesExist(from, to)) {
this.adjacency()[from][to] = AdjacencyMatrixGraph.EDGE_NONE;
this.adjacency()[to][from] = AdjacencyMatrixGraph.EDGE_NONE;
this.setNumberOfEdges(this.numberOfEdges() - 1);
return true;
}
}
return false;
}
/**
* this gives a list of vertices in the graph and their adjacencies
*
* @return returns a string describing this graph
*/
public String toString() {
String s = new String();
s = " ";
for (int i = 0; i < this.numberOfVertices(); i++) {
s = s + String.valueOf(i) + " ";
}
s = s + " \n";
for (int i = 0; i < this.numberOfVertices(); i++) {
s = s + String.valueOf(i) + " : ";
for (int j = 0; j < this.numberOfVertices(); j++) {
s = s + String.valueOf(this._adjacency[i][j]) + " ";
}
s = s + "\n";
}
return s;
}
}