Hello I have a problem when I call to function arrayBigToSmall the program crashes (after I enter the numbers). I want to understand why this happens and how I can fix this problem.?
Code -
#include <stdio.h>
#include <stdlib.h>
int main()
{
float array[2][3][2];
getNums(array);
return(0);
}
void getNums(float array[2][3][2])
{
int i,j,p;
printf("Enter numbers: \n");
for(i = 0; i < 2 ; i++)
{
for(j = 0; j < 3; j++)
{
for(p = 0; p < 2; p++)
{
scanf("%f",&array[i][j][p]);
}
}
}
arrayBigToSmall(array);
}
void arrayBigToSmall(float array[2][3][2])
{
int i,j,p,k;
float array1[12];
float temp;
for( i=0; i<3; i++)
{
for( j=0; j < 2; j++)
{
for(p = 0; p < 3; p++)
{
array1[k] = array[i][j][p];
k++;
}
}
}
}
for( i=0; i<3; i++)
{
for( j=0; j < 2; j++)
{
for(p = 0; p < 3; p++)
{
array1[k] = array[i][j][p];
k++;
}
}
}
}
k must be initialized to 0. i should be not greater than 2, j not greater that 3, and p not greater than 2
Be careful with size of array use following:
as the dimension of your array is 2 x 3 x 2 but in your code you are using 3 loops in 3 x 2 x 3 manner which overflows and which result in crash .
Also you should intialise k before using it.
void arrayBigToSmall(float array[2][3][2])
{
int i,j,p,k=0;
float array1[12];
float temp;
for( i=0; i<2; i++)
{
for( j=0; j < 3; j++)
{
for(p = 0; p <2 ; p++)
{
array1[k] = array[i][j][p];
k++;
}
}
}
}
Related
As the title says, I just want to paste this input into the program and then every number should be stored in 2D array.
Input:
172549683
645873219
389261745
496327851
813456972
257198436
964715328
731682594
528934167
My attempt:
#include <stdio.h>
int main() {
int array_2d[9][9];
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
scanf_s(" %d", &array_2d[i][j]);
}
}
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
printf("%d", array_2d[i][j]);
}
printf("\n");
}
}
This example shows how read whole number from a row and then split it into its digits that will be save into a 2D matrix.
#include <stdio.h>
int main() {
int array_2d[9][9];
int value = 0;
for (int i = 0; i < 9; i++) {
scanf("%d", &value);
int j = 8;
while (value != 0) {
array_2d[i][j--] = value % 10;
value = value / 10;
}
}
printf("\n\n");
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
printf("[%d]", array_2d[i][j]);
}
printf("\n");
}
}
I have taken two 2d arrays but the output is very different from expected.It should merge two 2d arrays into one 1d array.I want to merge two arrays.Not add.Everywhere the information and examples are about merging two 1D arrays.Please help someone.I don't know where I am wrong.
#include <stdio.h>
void print(int a[][3],int m);
int main()
{
int array1[3][3];
int array2[3][3];
int arraySum[6][3];
int k = 0; //put into array;
int l = 10;
for(int i = 0; i < 3; i++)
{
for(int j = 0; j < 3; j++)
{
array1[i][j] = ++k; //fill from 1 to 10
array2[i][j] = ++l; //fill from 11 - 19
}
}
/*merge arrays*/
for(int i = 0; i < 6; i++)
{
for(int j = 0; j < 3; j++)
{
(i < 3) ? arraySum[i][j] = array2[i][j] : arraySum[i][j] = array1[i-3][j];
//fill arraySum with array2 and append with array1.
//just so that arraySum does not have any order
}
}
printf("Arrays before sorting");
printf("Array 1: ");
print(array1,3);
printf("Array2: ");
print(array2,3);
printf("arraySum");
print(arraySum,6);
/* bubble sort*/
for(int i = 0; i < 6; i++)
{
for(int j = 0; j < 3; j++)
{
for(int k = i+1; k < 6; k++)
{
for(int m = 0; m < 3; m++)
{
if(arraySum[i][j] > arraySum[k][m])
{
//swap
int temp = arraySum[i][j];
arraySum[i][j] = arraySum[k][m];
arraySum[k][m] = temp;
}
}
}
}
}
printf("\n\n Merged Array after sorting");
print(arraySum,6);
return 0;
}
void print(int a[][3],int m)
{
for(int i = 0; i < m; i++)
{
for(int j = 0; j < 3; j++)
{
printf("%d" , a[i][j]);
}
}
}
I want to merge two arrays.Not add.Everywhere the information and examples are about merging two 1D arrays.Please help someone.I don't know where I am wrong.
Please try this code,To Merge two 2d arrays into one 1d array in C
#include <stdio.h>
void print(int a[][3],int m);
int main()
{
int array1[3][3];
int array2[3][3];
int arraySum[6][3];
int k = 0; //put into array;
int l = 10;
for(int i = 0; i < 3; i++)
{
for(int j = 0; j < 3; j++)
{
array1[i][j] = ++k; //fill from 1 to 10
array2[i][j] = ++l; //fill from 11 - 19
}
}
/*merge arrays*/
for(int i = 0; i < 6; i++)
{
for(int j = 0; j < 3; j++)
{
(i < 3) ? (arraySum[i][j] = array2[i][j]) : (arraySum[i][j] = array1[i-3][j]);
//fill arraySum with array2 and append with array1.
//just so that arraySum does not have any order
}
}
printf("Arrays before sorting");
printf("Array 1: ");
print(array1,3);
printf("Array2: ");
print(array2,3);
printf("arraySum");
print(arraySum,6);
/* bubble sort*/
for(int i = 0; i < 6; i++)
{
for(int j = 0; j < 3; j++)
{
for(int k = i+1; k < 6; k++)
{
for(int m = 0; m < 3; m++)
{
if(arraySum[i][j] > arraySum[k][m])
{
//swap
int temp = arraySum[i][j];
arraySum[i][j] = arraySum[k][m];
arraySum[k][m] = temp;
}
}
}
}
}
printf("\n\n Merged Array after sorting");
print(arraySum,6);
return 0;
}
void print(int a[][3],int m)
{
for(int i = 0; i < m; i++)
{
for(int j = 0; j < 3; j++)
{
printf("%d" , a[i][j]);
}
}
}
I hope this code will be usefull.
Thank you.
I believe you're trying to be too smart with ternary operator, you can do it simpler way:
if (i < 3)
arraySum[i][j] = array2[i][j];
else
arraySum[i][j] = array1[i-3][j];
Listen to your compiler it would've told you what was wrong if you've compiled with -Wall -Wextra.
And if you insist on using ternary then this would probably be clearer:
arraySum[i][j] = (i < 3) ? array2[i][j] : array1[i-3][j];
The title is pretty clear I think.
I am trying to create a program that calculates a 3x3 linear system using determinants, but I am getting a segmentation fault. Here is the code:
#include<stdio.h>
int determinant(int n, int m, int det[m][n])
{
int res;
res = det[0][0]*det[1][1] - det[0][1]*det[1][0];
return res;
}
int main(void)
{
int arr[3][4], det[2][2], i, j, D; //Dx1, Dx2, Dx3
for(i = 0; i < 3; i++)
{
printf("Eisagete tous suntelestes ths %dhs eksisoshs.", i+1);
scanf("%d %d %d %d", &arr[i][0], &arr[i][1], &arr[i][2], &arr[i][3]);
}
for(i = 0; i < 2; i++)
{
for(j = 0; j < 2; i++)
{
det[i][j] = arr[i+1][j+1];
}
}
D = arr[0][0]*determinant(2, 2, det);
for(i = 0; i < 2; i++)
{
for(j = 0; j < 2; i++)
{
det[i][j] = arr[i+1][j+((j == 1) ? 1 : 0)];
}
}
D -= arr[0][1]*determinant(2, 2, det);
for(i = 0; i < 2; i++)
{
for(j = 0; j < 2; i++)
{
det[i][j] = arr[i+1][j];
}
}
D += arr[0][2]*determinant(2, 2, det);
printf("%d\n", D);
}
I am getting the error right after completing the first for loop in main.
In the block:
for(i = 0; i < 2; i++)
{
for(j = 0; j < 2; i++)
{
det[i][j] = arr[i+1][j+1];
}
}
You increment i in both loops, and adding 1 more to it while reading from the array. So at arr[i+1] you are reading to far.
A segmentation fault basically means you are trying to read something you don't have access to.
You shoud never do what you're doing by passing static array sizes m and n as function argument:
int determinant(int n, int m, int det[m][n])
Check https://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html for info
#include <stdio.h>
#include <pthread.h>
int arr[1000][1000];
int brr[1000][1000];
int h;
int f;
void *BMM(void *arg)
{
int* neo = (int*) arg;
int ne = *neo;
int sum = 0;
for(int i = 0; i < n; ++i)
{
sum += arr[x][i]*brr[x][f];
++f;
}
printf("%d\n", sum);
crr[x][h] = sum;
pthread_exit(NULL);
}
int main()
{
pthread_t* ar = malloc(3*sizeof(*ar));
printf("Enter the value of m and n\n");
scanf("%d %d",&m,&n);
for(int i = 0; i < m; ++i)
{
for(int j = 0; j < n; ++j)
{
scanf("%d",&arr[i][j]);
}
}
printf("Enter the value of p and q\n");
scanf("%d %d",&p,&q);
if(p != n)
{
printf("The matrix multiplication is not possible\n");
return 0;
}
int* id;
id = (int *)malloc(4*sizeof(int));
for(int i = 0; i < p; ++i)
{
for(int j = 0; j < q; ++j)
{
scanf("%d",&brr[i][j]);
}
}
for(x = 0; x < m; ++x)
{
for(z = 0; z < q; z+=4)
{
f = z;
h = z;
for(int k = 0; k < 3; ++k)
{
pthread_create(&ar[k],NULL,BMM,NULL);
}
for(int k = 0; k < 3; ++k)
{
pthread_join(ar[k],NULL);
}
}
}
for (int i = 0; i < m; ++i)
{
for(int j = 0; j < q; ++j)
{
printf("%d ",crr[i][j]);
}
printf("\n");
}
}
The above program is supposed to multiply two matrix by multiplying row one of matrix by all the columns of other matrix using 3 threads and then row two by all the other columns and so on and then store the respective values int another matrix but it is giving segmentation fault. Where am I going wrong?
I think your problem is here:
pthread_create(&ar[k],NULL,BMM,NULL);
^^^^
void *arg is NULL
and then:
void *BMM(void *arg)
{
int* neo = (int*) arg;
int ne = *neo; // Dereference NULL --> segmentation fault
Further this looks strange:
void *BMM(void *arg)
{
int* neo = (int*) arg;
int ne = *neo; // ne is never used !!
int sum = 0;
for(int i = 0; i < n; ++i) // Where does n come from ?
Perhaps it should be n instead of ne?
If n, x, f and h are global variables you are into trouble as all threads will work on the same variables. That would be real bad. Each thread needs it own variables.
BTW:
Always check the value returned by scanf - something like:
if (scanf("%d %d",&m,&n) != 2)
{
// Add error handling here
}
and
if (scanf("%d",&arr[i][j]) != 1)
{
// Add error handling here
}
Im asking for help once again. This time I found myself in the midst of a task which I found on the internet and I cant find a good solution. At first I thought of bubble sort, but I didnt seem to find a way to use it with multidimensional array.
The task asks to find 3 smallest elements which arent repeating on the second array.
So far my code looks like this, though Ive removed a lot of it... Since it was a very wrong and futile aproach.
Everything was written in C.
Thanks for the help.
3
1 2 3
3 3 3
3 3 3
5 4 6
6 4 5
4 5 6
This is the given information for the file
#include stdio.h
#include stdlib.h
int main()
{
FILE *fptr;
fptr = fopen("Duomenys.txt", "r");
int i, j;
int k, l;
int bubbleTmp;
fscanf(fptr, "%d ", &k);
l = k;
int a[k][k];
int b[k][k];
for(i = 0; i < k; i++)
{
for(j = 0; j < l; j++)
{
fscanf(fptr,"%d ",&a[i][j]);
printf("%d ", a[i][j]);
}
printf("\n");
}
printf("\n\n\n");
for(i = 0; i < k; i++)
{
for(j = 0; j < l; j++)
{
fscanf(fptr,"%d ",&b[i][j]);
printf("%d ", b[i][j]);
}
printf("\n");
}
// Bubble Sort
for(i = 0; i < k; i++)
{
for(j = 0; j < l; j++)
{
if(a[i][j] > a[i][j+1])
{
}
}
}
fclose(fptr);
return 0;
}
To find the minimum and its position in the array:
int min = a[0][0], i_min = 0, j_min = 0;
for(i = 0; i < k; i++)
{
for(j = 0; j < l; j++)
{
if(a[i][j] < min)
{
min = a[i][j];
i_min = i;
j_min = j;
}
}
}
After the first try, you repeat it two more times, avoiding the minimums alrerady found. The positions of each minimums are known.
Previously, it was a suggestion.
Now, here is the solution:
//----------------------------------------------------------------------------
#include <iostream>
#include <iomanip>
#include <ctime>
//----------------------------------------------------------------------------
int **CreateArray (int N, int M)
{
int **arr = new int*[N];
for (int i = 0; i<N; i++)
arr[i] = new int [M];
for (int i = 0; i<N; i++)
for (int j = 0; j<M; j++)
arr[i][j] = rand()%10 - rand()%10;
return arr;
}
void DestroyArray (int **arr, int N)
{
for (int i = 0; i<N; i++)
delete [] arr[i];
delete [] arr;
}
void PrintArray (int **arr, int N, int M)
{
for (int i = 0; i<N; i++)
{
for (int j = 0; j<M; j++)
std::cout << std::setw(7) << arr[i][j];
std::cout << "\n";
}
std::cout << "\n";
}
//----------------------------------------------------------------------------
typedef struct _min
{
int value;
int i;
int j;
} TMin;
//---------------------------------------------------------------------------
void FindMin (int **arr, int N, int M, TMin **mins, int min_count)
{
mins[min_count]->value = arr[0][0];
mins[min_count]->i = 0;
mins[min_count]->j = 0;
for (int i = 0; i<N; i++)
for (int j = 0; j<M; j++)
{
if (arr[i][j] < mins[min_count]->value)
{
bool prev = false;
for (int k = 0; k<min_count; k++)
if (i == mins[k]->i && j == mins[k]->j)
{
prev = true;
break;
}
if (!prev)
{
mins[min_count]->value = arr[i][j];
mins[min_count]->i = i;
mins[min_count]->j = j;
}
}
}
}
//----------------------------------------------------------------------------
int main()
{
//array creation, filling, printing
srand ((unsigned int)time (NULL));
int N = 6, M = 7;
int **arr = CreateArray (N, M);
PrintArray (arr, N, M);
//container for 3 minimums
TMin **mins = new TMin*[3];
for (int i = 0; i<3; i++)
mins[i] = new TMin;
//let us find them
int min_count = -1;
while (++min_count < 3)
FindMin (arr, N, M, mins, min_count);
//result
for (int i = 0; i<3; i++)
std::cout << "arr[" << mins[i]->i << "][" <<mins[i]->j << "] = " << mins[i]->value << "\n";
//cleaning memory
for (int i = 0; i<3; i++)
delete [] mins[i];
delete [] mins;
DestroyArray (arr, N);
std::cin.sync();
std::cin.get();
return 0;
}
//-----------------------------------------------------------------------------