Hey guys, I am new to this forum, and I've been stuck in this problem for more than two days without any solution, so I really need you guys help.
Here is my code:
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#include <iostream>
#include <fstream>
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <sstream>
#define MAX_V 250
#define TRUE 1
#define FALSE 0
using namespace std;
typedef struct {
int vertex1;
int vertex2;
int weight;
int edge_deleted;
} Edge;
typedef struct {
int vertex[MAX_V];
int edges;
} Graph;
class G_kruskal {
private:
Edge E[MAX_V];
Graph T;
int total_vertex = 0;
int total_edge;
int clusters;
int adjmatrix[MAX_V][MAX_V]; // store matrix weight
public:
void kruskal();
void addEdge(Edge);
void build_adjmatrix(ifstream &fin);
void adjust();
Edge mincostEdge();
int cyclicT(Edge e);
void showEdge();
};
void G_kruskal::build_adjmatrix(ifstream &fin)
{
bool firstTrue = false;
bool secondTrue = false;
int numIn, max_vertex;
int vi = 0;
int vj = 0;
int count = 0;
string str;
fin.open("2.txt");
while (getline(fin, str)) {
if (str != "" && !(firstTrue)) {
stringstream stream(str);
while (1) {
int n;
stream >> n;
if (!stream) {
break;
}
max_vertex = n;
if (max_vertex > total_vertex) {
total_vertex = max_vertex;
max_vertex = 0;
}
}
}
else if (str == "" && !(secondTrue)) {
getline(fin, str);
firstTrue = true;
}
else if (str == "" && (secondTrue)) {
firstTrue = false;
getline(fin, str);
stringstream stream(str);
while (1) {
int n;
stream >> n;
if (!stream) {
break;
}
clusters = n;
}
}
if (firstTrue) {
secondTrue = true;
vi++;
vj = 0;
stringstream stream(str);
while (1) {
vj++;
int n;
stream >> n;
if (!stream) {
break;
}
if (n == -999) {
n = 0;
}
adjmatrix[vi][vj] = n;
}
}
}
total_vertex++;
}
void G_kruskal::adjust()
{
Edge e;
int i, j, weight;
total_edge = 0;
for (i = 1; i <= total_vertex; i++)
for (j = i + 1; j <= total_vertex; j++) {
weight = adjmatrix[i][j];
if (weight != 0) {
e.vertex1 = i;
e.vertex2 = j;
e.weight = weight;
e.edge_deleted = FALSE;
addEdge(e);
}
}
}
void G_kruskal::addEdge(Edge e)
{
E[++total_edge] = e;
}
void G_kruskal::showEdge()
{
int i = 1;
cout << "total vertex = " << total_vertex << " ";
cout << "total_edge = " << total_edge << "\n";
while (i <= total_edge) {
cout << "V" << E[i].vertex1 << " <-----> V" << E[i].vertex2
<< " weight= " << E[i].weight << "\n";
i++;
}
}
Edge G_kruskal::mincostEdge()
{
int i, min;
long minweight = INT_MAX;
for (i = 1; i <= total_edge; i++) {
if (!E[i].edge_deleted && E[i].weight < minweight) {
minweight = E[i].weight;
min = i;
}
}
E[min].edge_deleted = TRUE;
return E[min];
}
void G_kruskal::kruskal()
{
Edge e;
int i, loop = 1;
// init T
for (i = 1; i <= total_vertex; i++)
T.vertex[i] = 0;
T.edges = 0;
cout << "\nMinimum cost spanning tree using Kruskal\n";
cout << "-------------------------------------------\n";
while (T.edges != total_vertex - 1) {
e = mincostEdge();
if (!cyclicT(e)) {
cout << loop++ << "th min edge : ";
cout << "V" << e.vertex1 << " <----> V" << e.vertex2
<< " weight= " << e.weight << "\n";
}
}
}
int G_kruskal::cyclicT(Edge e)
{
int v1 = e.vertex1;
int v2 = e.vertex2;
T.vertex[v1]++;
T.vertex[v2]++;
T.edges++;
if (T.vertex[v1] >= 2 && T.vertex[v2] >= 2) {
if (v2 == 2)
return FALSE;
T.vertex[v1]--;
T.vertex[v2]--;
T.edges--;
return TRUE;
}
else
return FALSE;
}
int main()
{
G_kruskal obj;
ifstream fin;
obj.build_adjmatrix(fin);
obj.adjust();
obj.showEdge();
obj.kruskal();
fin.close();
system("PAUSE");
return 0;
}
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And here is my Input:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
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3 8
3 4
3
0 1 2 5 9
1 8
3 6 7
5 7 9
5 6 9
0 4
3 6 7
0 -999 -999 8 -999 -999 -999 -999 4 -999
-999 0 -999 2 3 -999 -999 -999 -999 -999
-999 -999 0 5 -999 -999 -999 -999 -999 -999
8 2 5 0 -999 11 -999 -999 -999 10
-999 3 -999 -999 0 -999 -999 -999 3 -999
-999 -999 -999 11 -999 0 2 8 -999 -999
-999 -999 -999 -999 -999 2 0 2 -999 8
-999 -999 -999 -999 -999 8 2 0 -999 3
4 -999 -999 -999 3 -999 -999 -999 0 -999
-999 -999 -999 10 -999 -999 8 3 -999 0
3
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For the first part of input file are the connections between each vertex, and the second part are the weight of the connections. The "-999" means there is no connection between two vertexes.
For what I'm doing here is that I need to input the file and draw the graph with Kruskal's Algorithm, which means I need to connect each vertex by lowest cost and without causing the cycle to the graph.
My problem is that when I try to execute my code, this error "Run-Time Check Failure #3 - The variable 'min' is being used without being initialized." shows up to my code
E[min].edge_deleted = TRUE;
in my mincostEdge() function. Since my code works fine to my other input:
1 2 3 4 5 6 7 8 9 10 11 12 13
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1 2 3 4
0 2 3
0 1 3
0 1 2
0
0 3 4 5 2
3 0 2 4 -999
4 2 0 1 -999
5 4 1 0 -999
2 -999 -999 -999 0
2
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Any idea for what is the reason for causing that?
My other question is that for the last line of the input file, there is a '3', which means clusters. Which after the algorithm, I need to break the graph into THREE part by cutting two highest edge. So the output will look like this:
Any idea for how should I do that according to my code.