algorithms/Graph.cpp at master · ngochaibui/algorithms · GitHub

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

#include<iostream>
#include<assert.h>

using namespace std;

//breasth first search from vertex v, n is the number of vertex (size of graph), marked[] is an array to mark if v is visited or not
void breadthFirstSearch(int v,int size,int marked[],int graph[][])
{
    Queue Q;
    Q.enQueue(v);
    marked[v]=1;
    while(!Q.empty())
    {
        int w = Q.getHead(); //w is temporary vertex
        for(int u=0;u<size;u++)
           if(graph[w][u]==1 && marked[u]==0){
              Q.enQueue(u);
              marked[u]=1;
           }
        Q.deQueue();
    }
}

void breadthFirstSearch_traversal(int size,int marked[],int graph[][])
{
    for(int v=0;v<size;v++)marked[v]=0;
    for(int v=0;v<size;v++)
        if(marked[v]==0)
            breadthFirstSearch(v,size,marked,graph);
}

void DepthFirstSearch(int v,int size,int marked[],int graph[][])
{
    marked[v]=1;
    for(int u=0;u<size;u++)
        if(graph[v][u]==1 && marked[u]==0){
            DepthFirstSearch(u,size,marked,graph);
        }
}

void DepthFirstSearch_traversal(int size,int marked[],int graph[][])
{
    for(int v=0;v<size;v++)marked[v]=0;
    for(int v=0;v<size;v++)
        if(marked[v]==0)
           DepthFirstSearch(v,size,marked,graph);
}

void topoSort(list T,int u,int size,int marked[],int graph[][])
{
    marked[u]=1;
    for(int v=0;v<size;v++)
        if(graph[u][v]==1 && marked[v]==0)
           topoSort(T,v,size,marked,graph);
    T.insert(0,u);
}

void topoSortGraph(list T,int size,int marked[],int graph[][])
{
    for(int u=0;u<size;u++)marked[u]=0;
    while(!T.empty()) T.del(T.length()-1);
    for(int u=0;u<size;u++)
        if(marked[u]==0)
           topoSort(T,u,size,marked,graph);
}
// ci is the label of the connected component
void FindConnectedComponent(int v,int ci,int size,int marked[],int graph[][])
{
    Queue Q;
    Q.enQueue(v);
    marked[v]=ci;
    while(!Q.empty())
    {
        int w = Q.getHead(); //w is the temporary visiting vertex
        for(int u=0;u<size;u++)
           if(graph[w][u]==1 && marked[u]==0){
              Q.enQueue(u);
              marked[u]=ci;
           }
        Q.deQueue();
    }
}

void FindAllConnectedComponent(int n,int marked[],int graph[][])
{
    for(int v=0;v<size;v++)marked[v]=0;
    int ci=1;
    for(int v=0;v<size;v++)
        if(marked[v]==0){
            FindConnectedComponent(v,ci,size,marked,graph);
            ci++;
        }
}

const int infinite = 32000;

float Dijkstra(int start,int end,int size,float weight[][],int path[])
{
    int marked[size];  //marked[] is an array to mark if v is visited or not
    for(int i=0;i<size;i++) marked[i]=0;
    marked[start]=1;
    float dist[size];
    for(int i=0;i<size;i++) dist[i]= infinite;
    dist[start]=0;
    int pre[size];
    for(int v=0;v<size;v++)
        if(weight[start][v]>0){
            dist[v] = weight[start][v];
            pre[v]  = start;
        }
    int u=start;
    while(u != end){
        int x; // temporary node
        for(int i=0;i<size;i++)
            if(marked[i]==0){
                x=i;
                break;
            }
        for(int i=0;i<size;i++)
           if(marked[i]==0 && dist[x]>dist[i]) x=i;
        u=x;        //select u with smallest dist in UnKnown set
        marked[u]=1;   // add u to Known
        for(int v=0;v<size;v++)
            if(marked[v]==0 && weight[u][v]>0 && (dist[u]+weight[u][v])< dist[v]) {
                dist[v]= dist[u] + weight[u][v];
                pre[v]=u;
            }
    }
	// save shorstest path to an array
    for(int i=0;i<size;i++)path[i]=0;
    path[0]=end+1;
    int k=1;
    int x=end;
    while(x!=start){
        x=pre[x];
        path[k++]=x+1;
    }
    return dist[end];
}