1 #include <iostream>
2 using namespace std;
3 // The shortest path
4
5 // Dijstra ’s algorithm: find the shortest path from a vertex to the remaining vertices
6 void printfPath ( int path [], int a) { // Output path algorithm
7 int stack [maxsize], top = -1 ;
8 while (path [a]! = -1 ) {
9 stack [++ top] = path [a];
10 a = path [a ];
11 }
12 while (top! = -1 ) {
13 cout<<stack[top--]<<" ";
14 }
15 cout<endl;
16 }
17 void Dijkstra(MGraph g,int v,int dist[],int path[]){
18 int set[maxsize];
19 int k,min;
20 for(int i=0;i<g.n;i++){//初始化
21 dist[i]=g.edges[v][i];
22 set[i]=0;
23 if(g.edges[v][i]<INF){
24 path[i]=v;
25 }else{
26 path[i]=-1;
27 }
28 }
29 set[v]=1;
30 path[v]=-1;
31 for(int i=0;i<g.n-1;i++){//两层循环
32 min=INF;
33 for(int j=0;j<g.n;j++){//Find the next vertex and put it into the set
34 if ( set [j] == 0 && dist [j] < min) {
35 k = j;
36 min = dist [j];
37 }
38 }
39 set [k] = 1 ;
40 for ( int j = 0 ; j <gn; j ++) { // Update the shortest path
41 if ( set [j] == 0 && dist [j]> dist [k] + edges [k] [j]) {
42 dist [j] = dist [k] + edges [k] [j];
43 path [j] = k;
44 }
45 }
46 }
47 }
48
49 // Freud algorithm: path between any pair of vertices
50 void printPath ( int u, int v, int path [] [maxsize]) { // Output path
51 if (path [u] [v] ==- 1 ) {
52 cout << u << " -> " << v << endl;
53 return ;
54 }
55 else {
56 int mid=path[u][v];
57 printPath(u,mid,path);
58 printPath(mid,v,path);
59 }
60 }
61 void Floyd(MGraph g,int path[][maxsize]){//复杂度为N^3;
62 int A[maxsize][naxsize];
63 for(int i=i;i<g.n;i++){//对A[][]和path[][]初始化
64 for(int j=0;j<g.n;j++){
65 A[i][j]=g.edges[i][j];
66 path[i][j]=-1;
67 }
68 }
69 for ( int k = 0 ; k <gn; k ++) { // The three-layer loop completes the detection and modification of all i, j with K as the intermediate point.
70 for ( int i = 0 ; i <gn; i ++ ) {
71 for ( int j = 0 ; j <gn; j ++ ) {
72 if (A [i] [j]> A [i] [k] + A [k] [j]) {
73 A [i] [j] = A [i] [K] + A [k] [j];
74 path [i] [j] = k;
75 }
76 }
77 }
78 }
79 }