Let the matrix have 4 verticles and 4 edge: (1,2),(1,4),(2,3),(2,4). I need to fill Adjacency (I did) and transform this Adjacency matrix to Incidence matrix. The result should be a matrix Incidence={(0111),(1010),(1101),(1010)} What is the best algorithm. I can't find a solution, all ideas are with bugs. :-( Thanks
#include "iostream"
#include "conio.h"
#include <stdlib.h>
using namespace std;
struct Rebro {
int x=0;
int y=0;
};
int main()
{
int Graph[100][100], Vertex, Edge, x, y;
int VG, EG;
int Incidence[100][100];
cout << "Enter number of vertexes:";
cin >> Vertex;
cout << "\nEnter number of edges:";
cin >> Edge;
//_________________________NULL
for (int i = 1; i <= Vertex; i++)
for (int j = 1; j <= Vertex; j++)
{
Graph[i][j] = 0;
}
//_________________________NULL
for (int i = 1; i <= Vertex; i++)
for (int j = 1; j <= Vertex; j++)
{
Incidence[i][j] = 0;
}
//_________________________INPUT
Rebro mass[100];
cout << "\nEnter edges:\n " << endl;
for (int i = 1; i <= Edge; i++)
{
cout << "e1=";
cin >> x;
cout << "e2=";
cin >> y;
cout << endl;
Graph[x][y] = 1;
Graph[y][x] = 1;
mass[i].x =x ;
mass[i].y =y ;
}
//_________________________OUTPUT
cout << "\nAdjacency matrix:\n" << endl;
for (int i = 1; i <= Vertex; i++)
{
for (int j = 1; j <= Vertex; j++)
{
cout <<" "<< Graph[i][j];
}
cout << endl;
}
cout << endl;
for (int i = 1; i <= Edge; i++) {
Incidence[i][mass[i].x] = 1;
Incidence[i][mass[i].y] = 1;
}
//_________________________OUTPUT
cout << "\nIncidence matrix:\n" << endl;
int count = 0;
for (int j = 1; j <= Vertex; j++)
{
for (int i = 1; i <= Vertex; i++)
{
cout << " " << Incidence[i][j];
}
cout << endl;
}
cout << endl;
_getch();
}
OR generally a wrong idea:
#include "iostream"
#include "conio.h"
#include <stdlib.h>
using namespace std;
int main()
{
int Graph[100][100], Vertex, Edge, x, y;
int VG, EG;
int Incidence[100][100];
cout << "Enter number of vertexes:";
cin >> Vertex;
cout << "\nEnter number of edges:";
cin >> Edge;
//_________________________NULL
for (int i = 1; i <= Vertex; i++)
for (int j = 1; j <= Vertex; j++)
{
Graph[i][j] = 0;
}
//_________________________NULL
for (int i = 1; i <= Vertex; i++)
for (int j = 1; j <= Vertex; j++)
{
Incidence[i][j] = 0;
}
//_________________________INPUT
cout << "\nEnter edges:\n " << endl;
for (int i = 1; i <= Edge; i++)
{
cout << "e1=";
cin >> x;
cout << "e2=";
cin >> y;
cout << endl;
Graph[x][y] = 1;
Graph[y][x] = 1;
}
//_________________________OUTPUT
cout << "\nAdjacency matrix:\n" << endl;
for (int i = 1; i <= Vertex; i++)
{
for (int j = 1; j <= Vertex; j++)
{
cout <<" "<< Graph[i][j];
}
cout << endl;
}
cout << endl;
for (int i =1; i<=Edge; i++) {
for (int j=1; j<=Edge; j++) {
if (Graph[x][y]==1) {
if ((i==x)||(i==y)||(j==x)||(j==y)) {
Incidence[i][j]==1;
Incidence[j][i]==1;
}
else {
Incidence[i][j]==0;
Incidence[j][i]==0;
}
}
}
}
//_________________________OUTPUT
cout << "\nIncidence matrix:\n" << endl;
int count = 0;
for (int j = 1; j <= Vertex; j++)
{
for (int i = 1; i <= Vertex; i++)
{
cout << " " << Incidence[i][j];
}
cout << endl;
}
cout << endl;
_getch();
}
Related
I am trying to create a program that swaps the row that contains the min number with the row that contains the max number in a n x m twodimensional array (c++)
#include <iostream>
using namespace std;
int main()
{
int i, j, n, m, imin, imax, jnm, jnv;
cin >> n >> m;
int k[n][m];
int max = 0;
int min = 0;
for (i = 0; i < n; i++) {
for (j = 0; j < m; j++) {
cout << "a[" << i << "][" << j << "]" << endl;
cin >> k[i][j];
}
}
cout << endl
<< endl;
for (i = 0; i < n; i++) {
for (j = 0; j < m; j++) {
cout << k[i][j];
}
cout << endl;
}
cout << endl
<< endl;
for (i = 0; i < n; i++) {
for (j = 0; j < m; j++) {
if (k[i][j] > max) {
max = k[i][j];
imax = i;
}
}
cout << endl;
}
min = max;
for (i = 0; i < n; i++) {
for (j = 0; j < m; j++) {
if (k[i][j] < min) {
min = k[i][j];
imin = i;
}
}
cout << endl;
}
cout << endl
<< endl;
if (imax == imin) {
cout << endl
<< "Min & Max are in the same row!" << endl;
}
else {
for (i = 0; i < n; i++) {
for (j = 0; j < m; j++) {
if (i == imax) {
k[i][j] = k[imin][j];
}
else if (i == imin) {
k[i][j] = k[imax][j];
}
cout << k[i][j];
}
cout << endl;
}
}
return 0;
}
I know the code isn't the cleanest and most professionally written, and that isn't important, as I'm currently preparing for a coding competition where the only thing that matters is functionality of the program.
When I execute this program, it usually swaps one row but the other is still the same.
You could use function swapif you want to swap. At the moment you assignments are wrong.
So, simply write:
#include <iostream>
#include <vector>
using namespace std;
int main()
{
int i, j, n, m, imin=0, imax=0;
cin >> n >> m;
vector<vector<int>> k(n, vector<int>(m, 0));
int max = 0;
int min = 0;
for (i = 0; i < n; i++) {
for (j = 0; j < m; j++) {
cout << "a[" << i << "][" << j << "]" << endl;
cin >> k[i][j];
}
}
cout << endl
<< endl;
for (i = 0; i < n; i++) {
for (j = 0; j < m; j++) {
cout << k[i][j] << ' ';
}
cout << endl;
}
cout << endl
<< endl;
for (i = 0; i < n; i++) {
for (j = 0; j < m; j++) {
if (k[i][j] > max) {
max = k[i][j];
imax = i;
}
}
cout << endl;
}
min = max;
for (i = 0; i < n; i++) {
for (j = 0; j < m; j++) {
if (k[i][j] < min) {
min = k[i][j];
imin = i;
}
}
cout << endl;
}
cout << endl
<< endl;
if (imax == imin) {
cout << endl
<< "Min & Max are in the same row!" << endl;
}
else {
for (j = 0; j < m; j++)
swap(k[imin][j], k[imax][j]);
for (i = 0; i < n; i++) {
for (j = 0; j < m; j++) {
cout << k[i][j] << ' ';
}
cout << endl;
}
}
return 0;
}
And sorry, I cannot write int k[n][m]; because this is not C++ and my compiler cannot compile it. But vector can be used in the same way.
If you are not allowed to use std::swapyou can use instead:
for (j = 0; j < m; j++) {
int tmp = k[imin][j];
k[imin][j] = k[imax][j];
k[imax][j] = tmp;
}
For the competition you could also get the min and max values already during input and write:
#include <iostream>
#include <vector>
#include <algorithm>
#include <limits>
int main()
{
// Read matrix size
size_t rows{}, columns{};
if (std::cin >> rows >> columns) {
// Here we will store our matrix
std::vector<std::vector<int>> matrix(rows, std::vector<int>(columns, 0));
// Initilize min max values
int maxElement = std::numeric_limits<int>::min();
int minElement = std::numeric_limits<int>::max();
size_t indexMaxRow{}, indexMinRow{};
// Enter values in matrix
for (size_t row{}; row < rows; ++row) {
for (size_t column{}; column < columns; ++column) {
std::cout << "array[" << row << "][" << column << "]\n";
if (std::cin >> matrix[row][column]) {
// Already during input find the min and max values
if (matrix[row][column] > maxElement) {
maxElement = matrix[row][column];
indexMaxRow = row;
}
if (matrix[row][column] < minElement) {
minElement = matrix[row][column];
indexMinRow = row;
}
}
}
}
// Show original matrix
std::cout << "\n\n\nYou entered:\n\n";
for (const auto& row : matrix) {
for (const auto& col : row) std::cout << col << ' ';
std::cout << '\n';
}
// Swap
std::swap(matrix[indexMaxRow], matrix[indexMinRow]);
// Show swapped matrix
std::cout << "\n\n\nSwapped:\n\n";
for (const auto& row : matrix) {
for (const auto& col : row) std::cout << col << ' ';
std::cout << '\n';
}
}
else std::cerr << "\nError while reading size\n";
}
learning graph theory in c++ here.
Sorry for the C-style codes.
I got an segmentation fault of my codes. I understand the meaning of it but have not learnt how to debug with IDE yet.
However I feel the bug is somewhere in my spanningtree() function. Could anyone point me out what could went wrong? The program is meant to print out the cost matrix, the minimum distance path and the total path cost. However, it exited after inputting.
#include <iostream>
using namespace std;
class prims
{
private:
int no_of_edges, no_of_nodes;
int graph[10][10],visited[10],mindist[10];
public:
void input();
void output();
void spanningtree();
prims()
{
no_of_edges = no_of_nodes = 0;
for (int i = 0; i<10; i++)
{
//assign visited minimum distance array to 0
visited[i] = mindist[i] = 0;
for (int j = 0; j<10; j++)
{
graph[i][j] = 0;
}
}
}
};
void prims::input()
{
int vertex1, vertex2, cost;
cout << "Enter no_of_nodes ";
cin >> no_of_nodes;
cout << "Enter the no_of_edges ";
cin >> no_of_edges;
for (int i = 0; i< no_of_edges; i++)
{
cout << "Enter vertex1 ";
cin >> vertex1;
cout << "Enter vertex2 ";
cin >> vertex2;
cout << "Enter the cost of " << vertex1 << " and " << vertex2 << " ";
cin >> cost;
graph[vertex1][vertex2]=graph[vertex2][vertex1]=cost;
}
}
void prims::output()
{
for (int i = 0; i < no_of_nodes; i++)
{
cout << endl;
for (int j = 0; j< no_of_nodes; j++)
{
cout.width(4);
cout << graph[i][j];
}
}
}
void prims::spanningtree()
{
int min = 9999, row, col, index = 0;
for (int i = 0; i < no_of_nodes; i++)
{
for(int j = i; j < no_of_nodes; j++)
{
if(graph[i][j]<min&&graph[i][j]!=0)
{
min = graph[i][j];
row = i;
col = j;
}
}
}
visited[row]=visited[col]=1;
mindist[index++]=min;
for (int i = 0; i < no_of_nodes - 2; i++)
{
min = 9999;
for (int j = 0; j < no_of_nodes; j++)
{
if(visited[j]==1)
{
for(int k = 0; j < no_of_nodes; k++)
{
if(graph[j][k]<min&&graph[j][k]!=0 && visited[k]==0)
{
min = graph[j][k];
row = j;
col = k;
}
}
}
}
mindist[index++]=min;
visited[row]=visited[col]=1;
}
int total = 0;
cout << endl;
cout << "Minimum distance path is ";
for (int i=0; i < no_of_nodes-1; i++)
{
cout << " " << mindist[i] << " ";
total = total + mindist[i];
}
cout << endl << "Total path cost is " << total;
}
int main()
{
prims obj;
obj.input();
obj.spanningtree();
obj.output();
return 0;
}
Taking some credits from the helpful comments/answers. Here is my revised codes. The main issue was the typo in one of the loop for(int k = 0; j < no_of_nodes; k++).
using namespace std;
class prims
{
private:
int no_of_edges, no_of_nodes;
int graph[10][10],visited[10],mindist[10];
public:
void input();
void output();
void spanningtree();
prims()
{
no_of_edges = no_of_nodes = 0;
for (int i = 0; i<10; i++)
{
//assign visited minimum distance array to 0
visited[i] = mindist[i] = 0;
for (int j = 0; j<10; j++)
{
graph[i][j] = 0;
}
}
}
};
void prims::input()
{
int vertex1, vertex2, cost;
cout << "Enter no_of_nodes ";
cin >> no_of_nodes;
cout << "Enter the no_of_edges ";
cin >> no_of_edges;
for (int i = 0; i< no_of_edges; i++)
{
cout << "Enter vertex1 ";
cin >> vertex1;
cout << "Enter vertex2 ";
cin >> vertex2;
cout << "Enter the cost of " << vertex1 << " and " << vertex2 << " ";
cin >> cost;
graph[vertex1][vertex2]=graph[vertex2][vertex1]=cost;
}
}
void prims::output()
{
for (int i = 0; i < no_of_nodes; i++)
{
cout << endl;
for (int j = 0; j< no_of_nodes; j++)
{
cout.width(4);
cout << graph[i][j]<<" ";
}
}
}
void prims::spanningtree()
{
int min = 9999, row, col, index = 0;
for (int i = 0; i < no_of_nodes; i++)
{
for(int j = i; j < no_of_nodes; j++)
{
if(graph[i][j]<min&&graph[i][j]!=0)
{
min = graph[i][j];
row = i;
col = j;
}
}
}
visited[row]=visited[col]=1;
mindist[index++]=min;
for (int i = 0; i < no_of_nodes - 2; i++)
{
min = 9999;
for (int j = 0; j < no_of_nodes; j++)
{
if(visited[j]==1)
{
for(int k = 0; k < no_of_nodes; k++)
{
if(graph[j][k]<min&&graph[j][k]!=0 && visited[k]==0)
{
min = graph[j][k];
row = j;
col = k;
}
}
}
}
mindist[index++]=min;
visited[row]=visited[col]=1;
}
int total = 0;
cout << endl;
cout << "Minimum distance path is ";
for (int i=0; i < no_of_nodes-1; i++)
{
cout << " " << mindist[i] << " ";
total = total + mindist[i];
}
cout << endl << "Total path cost is " << total << endl;
}
int main()
{
prims obj;
obj.input();
obj.spanningtree();
obj.output();
// return 0;
}
Your primary problem is not checking that indexes are in range (there is where c++ might help, but you can do it in c as well). Primary debugging tool - print. If you would print j and k before using them as array indexes you would solve your problem yourself
so i got this code.
int n;
int m=1;
int a=9;
cout<<"Enter N Number = ";
cin>>n;
n=n*2-1;
for(int y=1;y<=n;y++)
{
for(int x=1;x<=n;x++)
{
if(x==y+n/2 || x==y-n/2 || x==n-y+1-n/2 || x==n-y+1+n/2)
{
if(m<=9)
{
cout<<m++;
}
else if(m>9&&a>0)
{
a--;
cout<<a;
}
}
else
{
cout<<" ";
}
}
cout<<endl;
}
This is what i get :
Diamond Shape(Fail)
And what i expected is there's no number "0" on the bottom of the shape, so after it printed the number 1 its bounce back to number 2,3 and so on
pardon for my bad english
Do you want it to be like this?
Check this out!
I can code in Pascal, C++ and Java.
PS: I am not a native English speaker too.
First Answer: This is not the best answer, I will improve it tomorrow afternoon.
#include <iostream>
using namespace std;
int get() {
static int counter = 0;
static bool reverse = false;
!reverse ? counter++ : counter--;
if (counter==10 or counter==0) reverse = !reverse;
counter==10 ? counter = 8 : 0;
counter==0 ? counter = 2 : 0;
return counter;
}
int main() {
int number;
cout << "Enter N Number = ";
cin >> number;
//forward:
for (int i = 0; i < number; i++) {
for (int j = number-i-1; j > 0; j--)
cout << " ";
cout << get();
if (i!=0) {
for (int j = 0; j < i * 2 -1; j++) cout << " ";
cout << get();
}
cout << endl;
}
//backward:
for (int i = number-1; i > 0 ; i--) {
for (int j = number-i; j > 0; j--)
cout << " ";
cout << get();
if (i!=1) {
for (int j = i * 2 -3; j > 0; j--) cout << " ";
cout << get();
}
cout << endl;
}
return 0;
}
Second Answer: Improved loops
#include <iostream>
using namespace std;
int nextNumber() {
static int counter = 0;
static bool reverse = true;
!reverse ? counter++ : counter--;
if (counter==-1) counter=1;
if (counter==9 or counter==1) reverse = !reverse;
return counter;
}
int main() {
int number;
cout << "Enter N Number = ";
cin >> number;
int space = number;
int middle = -3;
for (int row = 0; row < number*2-1; row++) {
if(row<number) {
space--;
middle += 2;
}
else {
space++;
middle -= 2;
}
for (int i = 0; i < space; i++)
cout << " ";
cout << nextNumber();
if(row!=0 and row!=number*2-2) {
for (int i = 0; i < middle; i++)
cout << " ";
cout << nextNumber();
}
cout << endl;
}
return 0;
}
I want to compare elements for each line of a matrix, from smallest to biggest.
But I don't want to print the sorted array I want to print the original position.
0 11.80 79.34 78.23
11.80 0 65.23 45.19
79.34 65.23 0 90.27
78.23 45.19 90.27 0
In this Matrix for the first line I wanna print 1, 2, 4, 3
My Code so far:
#include <iostream>
#include <fstream>
#include <iomanip>
using namespace std;
int main() {
string dummy;
double myArray[4][4];
int i;
int j;
int y;
ifstream infile("dist.dat");
cout << "Open file " << "dist.dat" <<" for reading." << endl;
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
infile >> myArray[i][j];
if (!infile) {
cout << "***There was a problem trying to read element [" << i << "][" << j << "]" << endl;
return 0;
}
}
}
infile.close();
cout << "Here's the array from the file" << endl;
cout << fixed << setprecision(2);
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
cout << setw(10) << myArray[i][j];
}
cout << endl;
}
cout << endl;
int x = myArray[i][j];
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
if(myArray[i][j] >= x) {
x = j;
}
else {
x = j + 1;
}
}
cout << x << endl;
}
return 0;
}
You need to maintain another matrix which has indices of every line and then apply the same operations on it that you are applying on each line of the original matrix to sort it.
Here is the code:
#include <iostream>
#include <fstream>
#include <iomanip>
using namespace std;
void swap(int &x, int &y)
{
int temp = x;
x = y;
y = temp;
}
void swap(double &x, double &y)
{
double temp = x;
x = y;
y = temp;
}
int main()
{
string dummy;
double myArray[4][4];
int i;
int j;
int y;
int k;
ifstream infile("dist.dat");
cout << "Open file " << "dist.dat" <<" for reading." << endl;
for (i = 0; i < 4; i++)
{
for (j = 0; j < 4; j++)
{
infile >> myArray[i][j];
if (!infile)
{
cout << "***There was a problem trying to read element [" << i << "][" << j << "]" << endl;
return 0;
}
}
}
infile.close();
cout << "Here's the array from the file" << endl;
cout << fixed << setprecision(2);
for (i = 0; i < 4; i++)
{
for (j = 0; j < 4; j++)
{
cout << setw(10) << myArray[i][j];
}
cout << endl;
}
cout << endl;
int sortedIndices[4][4];
for (i = 0; i < 4; i++)
{
for (j = 0; j < 4; j++)
{
sortedIndices[i][j] = j+1;
}
}
int x;
for (i = 0; i < 4; i++)
{
for (j = 0; j < 4; j++)
{
x = j;
for(k = j+1; k < 4; k++)
{
if(myArray[i][k] < myArray[i][x])
{
x = k;
}
}
swap(sortedIndices[i][j], sortedIndices[i][x]);
swap(myArray[i][j], myArray[i][x]);
}
}
for (i = 0; i < 4; i++)
{
for (j = 0; j < 4; j++)
{
cout << setw(10) << sortedIndices[i][j];
}
cout<<endl;
}
return 0;
}
So me and my group have been working on this project for a few days we can get the top part too draw when we step into it but it does not run and we are not sure why it wont.
The first function is to draw the top and the second is to draw the bottom.
The top seems to draw fine i am not sure why the code will not even run.
#include<iostream>
using namespace std;
void drawTopPart(int userNum);
void drawBottomPart(int userNum);
int main() {
//declarations
int userNum;
//get user input
cout << "Enter an odd number from 1 to 15: ";
cin >> userNum;
//output
drawTopPart(userNum);
drawBottomPart(userNum);
cout << endl;
system("pause");
return 0;
}
void drawTopPart(int userNumPar) {
int z = 1;
int size;
cin >> size;
for (int i = 0; i <= size; i++) {
for (int j = size; j>i; j--) {
cout << " ";
}
cout << "*";
if (i>0) {
for (int k = 1; k <= z; k++) {
cout << " ";
} z += 2; cout << "*";
}
cout << endl;
}
}
void drawBottomPart(int userNumPar){
int z -= 4;
int size;
cin >> size;
for (int i = 0; i <= size - 1; i++) {
for (int j = 0; j <= i; j++) {
cout << " ";
}
cout << "*";
for (int k = 1; k <= z; k++) {
cout << " ";
}
z -= 2;
if (i != size - 1) {
cout << "*";
}
}
You have two mainly errors.
First,
void drawBottomPart(int userNumPar){
int z -= 4;
int size;
int z -= 4; have syntax error.You can change it int z = 17;
Second,you forget endl here.
if (i != size - 1) {
cout << "*";
}
cout << endl;