dijkstra algorithm c 2b 2b

1void dijkstra(int s) {
2  priority_queue<pair<int, int>, vector<pair<int, int> >, greater<pair<int, int> > > pq;
3  for (int i=0; i<N; i++) dist[i] = INF;
4  dist[s] = 0;
5  pq.push(make_pair(0, s));
6  while (!pq.empty()) {
7    pair<int, int> front = pq.top();
8    pq.pop();
9    int w = front.first, u = front.second;
10    if (w > dist[u]) continue;
11    for (int i=0; i<adj[u].size(); i++) {
12      pair<int, int> v = adj[u][i];
13      if (dist[v.first] > dist[u] + v.second) {
14        dist[v.first] = dist[u] + v.second;
15        pq.push(make_pair(dist[v.first], v.first));
16      }
17    }
18  }
19}

1#include<bits/stdc++.h>
2using namespace std;
3
4int main()
5{
6	int n = 9;
7	
8	int mat[9][9] = { { 100,4,100,100,100,100,100,8,100}, 
9                      { 4,100,8,100,100,100,100,11,100}, 
10                      {100,8,100,7,100,4,100,100,2}, 
11                      {100,100,7,100,9,14,100,100,100}, 
12                      {100,100,100,9,100,100,100,100,100}, 
13                      {100,100,4,14,10,100,2,100,100}, 
14                      {100,100,100,100,100,2,100,1,6}, 
15                      {8,11,100,100,100,100,1,100,7}, 
16                      {100,100,2,100,100,100,6,7,100}};
17	
18	int src = 0;
19	int count = 1;
20	
21	int path[n];
22	for(int i=0;i<n;i++)
23		path[i] = mat[src][i];
24	
25	int visited[n] = {0};
26	visited[src] = 1;
27	
28	while(count<n)
29	{
30		int minNode;
31		int minVal = 100;
32		
33		for(int i=0;i<n;i++)
34			if(visited[i] == 0 && path[i]<minVal)
35			{
36				minVal = path[i];
37				minNode = i;
38			}
39		
40		visited[minNode] = 1;
41		
42		for(int i=0;i<n;i++)
43			if(visited[i] == 0)
44				path[i] = min(path[i],minVal+mat[minNode][i]);
45					
46		count++;
47	}
48	
49	path[src] = 0;
50	for(int i=0;i<n;i++)
51		cout<<src<<" -> "<<path[i]<<endl;
52	
53	return(0);
54}

1#include <limits.h> 
2#include <stdio.h> 
3  
4
5#define V 9 
6  
7
8int minDistance(int dist[], bool sptSet[]) 
9{ 
10
11    int min = INT_MAX, min_index; 
12  
13    for (int v = 0; v < V; v++) 
14        if (sptSet[v] == false && dist[v] <= min) 
15            min = dist[v], min_index = v; 
16  
17    return min_index; 
18} 
19  
20
21void printSolution(int dist[]) 
22{ 
23    printf("Vertex \t\t Distance from Source\n"); 
24    for (int i = 0; i < V; i++) 
25        printf("%d \t\t %d\n", i, dist[i]); 
26} 
27  
28
29void dijkstra(int graph[V][V], int src) 
30{ 
31    int dist[V]; 
32    
33  
34    bool sptSet[V];
35 
36    for (int i = 0; i < V; i++) 
37        dist[i] = INT_MAX, sptSet[i] = false; 
38  
39  
40    dist[src] = 0; 
41  
42  
43    for (int count = 0; count < V - 1; count++) { 
44       
45        int u = minDistance(dist, sptSet); 
46  
47       
48        sptSet[u] = true; 
49  
50       
51        for (int v = 0; v < V; v++) 
52  
53           
54            if (!sptSet[v] && graph[u][v] && dist[u] != INT_MAX 
55                && dist[u] + graph[u][v] < dist[v]) 
56                dist[v] = dist[u] + graph[u][v]; 
57    } 
58  
59 
60    printSolution(dist); 
61} 
62  
63
64int main() 
65{ 
66    
67    int graph[V][V] = { { 0, 4, 0, 0, 0, 0, 0, 8, 0 }, 
68                        { 4, 0, 8, 0, 0, 0, 0, 11, 0 }, 
69                        { 0, 8, 0, 7, 0, 4, 0, 0, 2 }, 
70                        { 0, 0, 7, 0, 9, 14, 0, 0, 0 }, 
71                        { 0, 0, 0, 9, 0, 10, 0, 0, 0 }, 
72                        { 0, 0, 4, 14, 10, 0, 2, 0, 0 }, 
73                        { 0, 0, 0, 0, 0, 2, 0, 1, 6 }, 
74                        { 8, 11, 0, 0, 0, 0, 1, 0, 7 }, 
75                        { 0, 0, 2, 0, 0, 0, 6, 7, 0 } }; 
76  
77    dijkstra(graph, 0); 
78  
79    return 0; 
80} 

1const int INF = 1000000000;
2vector<vector<pair<int, int>>> adj;
3
4void dijkstra(int s, vector<int> & d, vector<int> & p) {
5    int n = adj.size();
6    d.assign(n, INF);
7    p.assign(n, -1);
8    vector<bool> u(n, false);
9
10    d[s] = 0;
11    for (int i = 0; i < n; i++) {
12        int v = -1;
13        for (int j = 0; j < n; j++) {
14            if (!u[j] && (v == -1 || d[j] < d[v]))
15                v = j;
16        }
17
18        if (d[v] == INF)
19            break;
20
21        u[v] = true;
22        for (auto edge : adj[v]) {
23            int to = edge.first;
24            int len = edge.second;
25
26            if (d[v] + len < d[to]) {
27                d[to] = d[v] + len;
28                p[to] = v;
29            }
30        }
31    }
32}
33