C++ Program to Find SSSP(Single Source Shortest Path) in DAG(Directed Acyclic Graphs)

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This C++ program displays the shortest path traversal from a particular node to every other node present inside the graph relative to the former node.

Here is the source code of the C++ program of the Djikstra’s Algoritm of finding shortest paths from the first node in graph to every other node with the shortest path length displayed beside each pair of vertices.This C++ program is successfully compiled and run on DevCpp,a C++ compiler.The program output is given below.

  1. /*
  2.  * C++ Program to find SSSP(Single Source Shortest Path) 
  3.  * in DAG(Directed Acyclic Graphs)
  4.  */
  5. #include <iostream>
  6. #include <conio.h>
  7. using namespace std;
  8. #define INFINITY 999
  9. struct node
  10. {
  11.    int from;
  12. }p[7];
  13. int c = 0;
  14. void djikstras(int *a,int b[][7],int *dv)
  15. {
  16.     int i = 0,j,min,temp;
  17.     a[i] = 1;
  18.     dv[i] = 0;
  19.     p[i].from = 0;
  20.     for (i = 0; i < 7;i++)
  21.     {
  22.         if (b[0][i] == 0)
  23.         {
  24.             continue;
  25.         }
  26.         else
  27.         {
  28.             dv[i] = b[0][i];
  29.             p[i].from = 0;
  30.         }
  31.     }
  32.     while (c < 6)
  33.     {
  34.         min = INFINITY;
  35.         for (i = 0; i < 7; i++)
  36.         {
  37.             if (min <= dv[i] || dv[i] == 0 || a[i] == 1)
  38.             {
  39.                 continue;
  40.             }
  41.             else if (min > dv[i])
  42.             {
  43.                 min = dv[i];
  44.             }
  45.         }
  46.         for (int k = 0; k < 7; k++)
  47.         {
  48.             if (min == dv[k])
  49.             {
  50.                 temp = k;
  51.                 break;
  52.             }
  53.             else
  54.             {
  55.                 continue;
  56.     	    }
  57.         }
  58.         a[temp] = 1;
  59.         for (j = 0; j < 7; j++)
  60.         {
  61.             if (a[j] == 1 || b[temp][j] == 0)
  62.             {
  63.                 continue;
  64.             }
  65.             else if (a[j] != 1)
  66.             {
  67.                 if (dv[j] > (dv[temp] + b[temp][j]))
  68.                 {
  69.                     dv[j] = dv[temp] + b[temp][j];
  70.                     p[i].from = temp;
  71.                 }
  72.             }
  73.         }
  74.         c++;
  75.     }  
  76.     for (int i = 0; i < 7; i++)
  77.     {
  78.         cout<<"from node "<<p[i].from<<" cost is:"<<dv[i]<<endl;
  79.     } 
  80. }       
  81. int main()
  82. {
  83.     int a[7];
  84.     int dv[7];
  85.     for(int k = 0; k < 7; k++)
  86.     {
  87.         dv[k] = INFINITY;
  88.     }
  89.     for (int i = 0; i < 7; i++)
  90.     {
  91.         a[i] = 0;
  92.     }
  93.     int b[7][7];
  94.     for (int i = 0;i < 7;i++)
  95.     {
  96.         cout<<"enter values for "<<(i+1)<<" row"<<endl;
  97.         for(int j = 0;j < 7;j++)
  98.         {
  99.             cin>>b[i][j];
  100.         }
  101.     }
  102.     djikstras(a,b,dv);
  103.     getch();
  104. }

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Output
enter values for 1 row
0
3
6
0
0
0
0
enter values for 2 row
3
0
2
4
0
0
0
enter values for 3 row
6
2
0
1
4
2
0
enter values for 4 row
0
4
1
0
2
0
4
enter values for 5 row
0
0
4
2
0
2
1
enter values for 6 row
0
0
2
0
2
0
1
enter values for 7 row
0
0
0
4
1
1
0
from node 0 to node 0 minimum cost is:0
from node 0 to node 1 minimum cost is:3
from node 0 to node 2 minimum cost is:5
from node 0 to node 3 minimum cost is:6
from node 0 to node 4 minimum cost is:8
from node 0 to node 5 minimum cost is:7
from node 0 to node 6 minimum cost is:8

Sanfoundry Global Education & Learning Series – 1000 C Programs.

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Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer & SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage, Advanced C Programming, SAN Storage Technologies, SCSI Internals & Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him @ LinkedIn