Adjaceny matrix for dijkstra shortest path algorithm

GillesCplusplus (9)
Hi guys, I want to apply dijkstra shortest path algorithm to the following 2 files:
projet14_milestone.txt
projet14_process.txt

projet14_milestone.txt looks like :
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12
0,5,Start
1,1,A
4,1,B
7,1,C
2,2,D
1,3,E
2,4,F
6,2,G
7,3,H
5,4,I
7,4,J
4,3,End


12 is the number of stages I need to consider and is stored in the variable nb.
From then on , the first number respresents the x coordinate of a stage, the second number respresents the y coordinate of a stage and then we can see the name of the stage. So for example line 2 : The x-coordinate of stage 'start' is 0 and is stored in milestone_x, the y coordinate of the stage 'start' is 5 and is stored in milestone_y. the name of the stage is stored in milestone_nom.




projet14_process.txt looks like : 
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PROCESS1,-3.88,Start,A
PROCESS2,-5.2,Start,B
PROCESS3,-7.97,Start,C
PROCESS4,-0.43,A,D
PROCESS5,-2.2,B,D
PROCESS6,-1.2,C,G
PROCESS7,-3.18,D,G
PROCESS8,-0.42,E,D
PROCESS9,-0.69,H,G
PROCESS10,-0.94,H,J
PROCESS11,-1.64,H,I
PROCESS12,-1.49,J,I
PROCESS13,-2.4,I,F
PROCESS14,-0.58,E,F
PROCESS15,-1.22,End,I
PROCESS16,-1.24,End,F

There are 16 different processes and each process consumes a certain amount of paint. Each process is defined by 2 stages. For example process 1 consumes -3,88 units of paint and connects stage 'start' with A. As it is and undirected graph, D->G consumes the same amount as G->D.

Thus far, I've written a code to become the adjacency matrix. The first row represents start, the second A, and so on. The first column represents start, the second A, and so on. As process 1 connects start with A, adjmatrix [0][1]= -3,88 and adjmatrix [1][0]= -3,88

But this code cannot attach the value -3,88 to this step, can someone help me?

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#include <iostream>
#include <fstream>
#include <cstring> 
#include <string>
using namespace std;



class Algorithme {

	private:
		int i= 0;

		struct milestone
				{
					int milestone_x;
					int milestone_y;
					char milestone_nom[6];
				};

		int nb = 12;
		milestone node[12];


		struct process
			{
			  char process_nom[20];
			  float process_consomation;
			  char process_node1[6];
			  char process_node2[6];
						};
		process procedure[16];


	public:

		void lecture();
		void adjmatr();


};





void Algorithme::lecture() {
// lecture document 1


	string ligne;

	ifstream infile;
	infile.open("/Users/gillescorswarem/documents/projet14_milestone.txt"); 

	if (infile.fail()) {
		cout << "erreur de lecture: document: milestone\n";
	}


		infile >> nb; 


	for ( i=0; i < nb;i++) {

		getline(infile,ligne,',');
				node[i].milestone_x = std::atoi(ligne.c_str());

		getline(infile,ligne,',');
					node[i].milestone_y = std::atoi(ligne.c_str());
		getline(infile,ligne);
				   strcpy(node[i].milestone_nom, ligne.c_str()); 
		}


	infile.close();



	string ligne2;
	ifstream infile2;
	infile2.open("/Users/gillescorswarem/documents/projet14_process.txt"); 
	if (infile2.fail())
		cout << "erreur de lecture: document: process\n";



	for ( i=0; i < 16;i++) {

	   getline(infile2,ligne2,',');
					strcpy(procedure[i].process_nom, ligne2.c_str()); 

		getline(infile2,ligne2,',');
					procedure[i].process_consomation = std::atof(ligne2.c_str()); 

		getline(infile2,ligne2,',');
					strcpy(procedure[i].process_node1, ligne2.c_str());

		getline(infile2,ligne2);
					strcpy(procedure[i].process_node2, ligne2.c_str()); 


		}
	infile2.close();

		
}

void Algorithme::adjmatr() {
	float adjmatrix [12][12];
	for (int a=0; a<16; a++){
		for (int b=0; b<12; b++){
			if (strcmp(procedure[a].process_node1,node[b].milestone_nom) == 0) {
					for (int c=0;c<12;c++){
							if ( strcmp (procedure[a].process_node2,node[c].milestone_nom) == 0)	{
								adjmatrix[b][c]= procedure[a].process_consomation;
								adjmatrix[c][b]= procedure[a].process_consomation;
							}

					}
		}
	}
	}


	cout << adjmatrix [0][1] << endl;
	cout << adjmatrix [4][7] << endl;



}


int main() {
	Algorithme reponse;
	reponse.lecture();
	reponse.adjmatr();
	return 0;
}





ne555 (10692)
this is the matrix read 
##### -3.88 -5.20 -7.97 ##### ##### ##### ##### ##### ##### ##### ##### 
-3.88 ##### ##### ##### -0.43 ##### ##### ##### ##### ##### ##### ##### 
-5.20 ##### ##### ##### -2.20 ##### ##### ##### ##### ##### ##### ##### 
-7.97 ##### ##### ##### ##### ##### ##### -1.20 ##### ##### ##### ##### 
##### -0.43 -2.20 ##### ##### -0.42 ##### -3.18 ##### ##### ##### ##### 
##### ##### ##### ##### -0.42 ##### -0.58 ##### ##### ##### ##### ##### 
##### ##### ##### ##### ##### -0.58 ##### ##### ##### -2.40 ##### -1.24 
##### ##### ##### -1.20 -3.18 ##### ##### ##### -0.69 ##### ##### ##### 
##### ##### ##### ##### ##### ##### ##### -0.69 ##### -1.64 -0.94 ##### 
##### ##### ##### ##### ##### ##### -2.40 ##### -1.64 ##### -1.49 -1.22 
##### ##### ##### ##### ##### ##### ##### ##### -0.94 -1.49 ##### ##### 
##### ##### ##### ##### ##### ##### -1.24 ##### ##### -1.22 ##### #####
(##### means no value) ¿is that correct? ¿do you get something different?

you should initialise all the elements of `adjmatrix' to an "infinite" value or you'll end up with extra edges.
GillesCplusplus (9)
This is indeed the matrix I have to become!
I want to replace all the ##### by the value 0 or infinity. 0 is also possible I believe, because I am working with negative values

But when I run the program and try to print adjmatrix [0][1] and adjmatrix [4][7] I always get the value 0.
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cout << adjmatrix [0][1] << endl;
cout << adjmatrix [4][7] << endl;


According to the matrix, adjmatrix [0][1] has to be equal to -3,88 and adjmatrix [4][7] to -3,18. Why does the program print 0 each time?
Last edited on
ne555 (10692)
I don't see any particular wrong in your code, and it does work in my end.
initialise `adjmatrix' and print it fully

may use a debugger to see if you do reach line 116 and to inspect the `procedure' and `node' arrays after reading from the files.
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