Why just looping the last input? - arrays

so I wanna make a program to find each sum of the columns of a matrix. In this code first you can input how many matrix you want and the second input is the size of matrix (n x n) and third input is the value of matrix.
The output must be each sum of the columns of matrix
here is the code
#include <stdio.h>
int main ()
{
int x, y, z;
int inp1, inp2;
int matrix[100][100];
int matrix2;
scanf("%d", &inp1);
for(z = 0; z < inp1; z++){
scanf("%d", &inp2);
for(x = 0; x < inp2; x++){
for(y = 0; y < inp2; y++){
scanf("%d", &matrix[x][y]);
}
}
}
for(z = 0; z < inp1; z++){
printf("Case #%d:", z+1);
for(x = 0; x < inp2; x++){
matrix2 = 0;
for(y = 0; y < inp2; y++){
matrix2 += matrix[y][x];
if(y == inp2-1){
printf(" %d", matrix2);
}
}
}
printf("\n");
}
return 0;
}
here's the input and ouput for that code
2 //first input (how many matrix)
2 //second input (size of matrix)
1 2 //third input (matrix)
1 2
3
1 1 1
2 2 2
3 4 5
Case #1: 6 7 8
Case #2: 6 7 8
for the second output is correct but the first output is wrong.
output for the second one from 1+2+3 = 6, 1+2+4 = 7, 1+2+5 = 8
What I want is the output for the first case is 2 and 4

Related

an effective way to convert from a number to its position on a matrix

I want to make an input system that will allow the user to choose a number and it will return the position of choice.
for example:
| 0 1 2
--+----------
0 | 1 2 3
1 | 4 5 6
2 | 7 8 9
in this matrix, if the user input is 5 it should return the position {1, 1} and if the input is 8 it should return {2, 1}.
I wrote a piece of code to try and do that but it doesn't work well for every scenario:
here is the code I wrote in C language:
VectorPos RequestInput(char arr[][3])
{
char input;
int converted;
VectorPos loc;
while (1)
{
printf("Enter number between 1-9: ");
scanf(" %c", &input);
if (input < '1' || input > '9')
printf("Invalid board Location.\n\n");
else
break;
}
converted = atoi(&input);
int count = 1;
int i, k;
i = k = 0;
for (k = 0; k < 3 && count++ < converted; k++)
{
for (i = 0; i < 3 && count++ < converted; i++);
}
loc.col = k;
loc.row = i;
return loc;
}
*VectorPos is just a struct to return a row and col in one variable.
I would like to ask if you know of any good more effective way of doing this.
thanks:)
For a rectangular grid like that, all you need is division and modulo:
// pos = position in grid from 1..
// w = grid width
// x = output x variable (range 0..w-1)
// y = output y variable (range 0..infinity)
// usage: pos_to_xy(4, 3, &x, &y);
void pos_to_xy(int pos, int w, int *x, int *y) {
pos -= 1; // Bring range 1.. to 0..
*y = pos / w;
*x = pos % w;
}
Example:
int main() {
for(int i = 1; i <= 9; i++) {
int x, y;
pos_to_xy(i, 3, &x, &y);
printf("%d: (x %d, y %d)\n", i, x, y);
}
return 0;
}
Output:
1: (x 0, y 0)
2: (x 1, y 0)
3: (x 2, y 0)
4: (x 0, y 1)
5: (x 1, y 1)
6: (x 2, y 1)
7: (x 0, y 2)
8: (x 1, y 2)
9: (x 2, y 2)

counter to check if array X is subsequence of A not working (C)

I've tried following this program by hand, but I still can't get it to work.
I have an array A = [4,3,2,1,4,3,2,1,4,3,2,1,4,3,2,1,4,3,2,1] and array X = [1,2,3].
I need to find the max number i for X^i that is a subsequence of A, and do this by binary search.
Since size of A is 20, and size of X is 3, the max possible i = 20/3 = 6. So my search will start at i = 3, which means that X^3 = [1,1,1,2,2,2,3,3,3].
This is not a subsequence of A, so binary search repeats for i = 1, X^1 = [1,2,3].
This is a subsequence of A, meaning it should pass and binary search should try again for i = 2.
However, my condition to see if the iteration passes or not is not working properly.
Here is the code:
#include <stdio.h>
#include <stdlib.h>
void create_initial_arrays(int size_a, int *A, int size_x, int *X);
void binary_search(int size_a, int * A, int size_x, int *X, int max_i, int min_i);
int main(){
int size_a, size_x;
scanf("%d", &size_a);
scanf("%d", &size_x);
int max_i = size_a / size_x;
int min_i = 0;
printf("Max: %d\n", max_i);
int *A = (int*) malloc(size_a *sizeof(int));
int *X = (int*) malloc(size_x *sizeof(int));
create_initial_arrays(size_a, A, size_x, X);
printf("Old X: ");
for(int i = 0; i < size_x; i++){
printf("%d ", X[i]);
}
printf("\n");
binary_search(size_a, A, size_x, X, max_i, min_i);
free(X);
free(A);
}
void create_initial_arrays(int size_a, int *A, int size_x, int *X){
int i, throwaway;
for(i = 0; i < size_a; i++){
scanf("%d", &A[i]);
}
scanf("%d", &throwaway);
for(i = 0; i < size_x; i++){
scanf("%d", &X[i]);
}
scanf("%d", &throwaway);
}
void binary_search(int size_a, int * A, int size_x, int *X, int max_i, int min_i){
int j, k, max_repeat = 0;
while(min_i <= max_i){
int i = 0, count = 0, repeats = (max_i + min_i)/2;
printf("\n");
int * temp = (int*) malloc(size_x * sizeof(int) * repeats);
for(k = 0; k < size_x; ++k){
for(j = 0; j < repeats; ++j){
temp[k * repeats + j] = X[k];
}
}
printf("New X: ");
for(i = 0; i < size_x * repeats; i++){
printf("%d ", temp[i]);
}
printf("A: ");
for (i = 0; i < size_a; i++){
printf("%d ", A[i]);
}
for(j = 0; j < size_a; j++){
if(A[j] == temp[i]){
count++;
i++;
}
}
printf("Count: %d", count);
if (count >= size_x * repeats){
printf("Low: %d Mid %d High % d Passes\n", min_i, repeats, max_i);
min_i = repeats + 1;
max_repeat++;
}
else{
printf("Low: %d Mid %d High % d Fails\n", min_i, repeats, max_i);
max_i = repeats - 1;
}
free(temp);
}
printf("Max repeat: %d", max_repeat);
}
And this is the section that I think must be problematic:
for(j = 0; j < size_a; j++){
if(A[j] == temp[i]){
count++;
i++;
}
}
I've output both Arrays to make sure they are populated correctly (they are) and the counter after each iteration. Here is my code output:
Old X: 1 2 3
New X: 1 1 1 2 2 2 3 3 3 A: 4 3 2 1 4 3 2 1 4 3 2 1 4 3 2 1 4 3 2 1 Count: 0Low: 0 Mid 3 High 6 Fails
New X: 1 2 3 A: 4 3 2 1 4 3 2 1 4 3 2 1 4 3 2 1 4 3 2 1 Count: 0Low: 0 Mid 1 High 2 Fails
New X: A: 4 3 2 1 4 3 2 1 4 3 2 1 4 3 2 1 4 3 2 1 Count: 0Low: 0 Mid 0 High 0 Passes
Max repeat: 1
Notice that count remains 0 throughout. On the first iteration for X^3 = [1,1,1,2,2,2,3,3,3], the condition is true 5 times ([1,1,1,2,2] is a subsequence of A, so count should be 5, but 5 is not >= size_x * repeats(3 * 3), so it fails as expected. Binary search reduces to Low 0 Mid 1 High 2, so i = repeats = 1.
X^1 = [1,2,3] is a subsequence of A, and count should be 5 on this iteration ([1,2,3] plus two extra counts of 3) which is >= size_x * repeats (3*1), so it should pass, and redo the search for i = 2. However, count remains zero and fails.
Why is count not updating? I know I need to keep it in the loop because I need it reset to 0 for each iteration, but I don't really understand why A[j] == temp[i] is not ever passing.

How to printf a list of values?

When I Enter new values they should display in View as a list like
1. 1 2 3 4 5 //first values
2. 6 5 9 8 3 // second values
3. 4 2 3 8 5 // ...
but instead it prints just the first values to the whole list. I try to fix this wihout a 2d array if possible. Any ideas?
#include <stdio.h>
#define LENGTH 5
const char *menuMsg = "\n\n\t Menu \n\n\t v (View)\n\t e (Enter)\n\t q (Quit)\n";
int main(){
int run = 1;
while(run){
puts(menuMsg);
char choice;
scanf(" %c", &choice);
int x, z;
int a[LENGTH];
int list=6;
if(choice=='e') {
for(x=0; x<LENGTH; x++){
printf("Enter nr.%d: ", x+1);
scanf("%d", &a[x]);
}
z++;
}
else if(choice=='v') {
for(z=0; z<list; z++){
printf("\n%d. ", z+1);
for(x=0; x<LENGTH; x++){
printf("%d ", a[x]);
}
}
}
else if(choice=='q') run = 0;
}
return 0;
}
The length of your array a is only 5. I'm concerned about where you define it since you expect it to print out 6 rows of 5 values- 30 individual numbers.
This might work, modify to your needs:
#define LENGTH 5 // amount in a row (number of cols)
#define HEIGHT 6 // amount of rows
a[LENGTH * HEIGHT] = { 0, 2, 3, 4...};
for (z=0; z < HEIGHT; z++){
printf("\n%d. ", z+1);
for (x=0; x < LENGTH; x++){
printf("%d ", a[x + LENGTH*z]);
}
}

How can I calculate the moving average of the array?

In Question, When an array X of size n and a degree k are input,
Write a program that calculates the k-th moving average of array X.
The kth-order moving average of the array X consisting of primitive data values is the average of the last k elements up to the i-th point of X.
That is, A [i] = (X [i-k + 1] + X [i-k + 2] + ... + X [i]) / k.
If the number of the preceding element (including itself) is smaller than k,
Calculate as an average.
For example, if array X is as follows and k is 3, X = 1 3 2 10 6 8
The third moving average is as follows.
A = 1 2 2 5 6 8 A [1] = (1 + 3) / 2, A [2] = (1 + 3 + 2) / 3
However, the program must have the execution time of O (n), not O (nk).
Round off the decimal point in the average calculation and obtain it as an integer.
For exact rounding, do not use% .f, but round it using the int property.
int main()
{
int i, n1, k;
int *array1;
scanf("%d", &n1);
array1 = (int *)malloc(sizeof(int)*n1);
scanf("%d", &k);
for (i = 0; i < n1; i++)
{
scanf("%d", &array1[i]);
}
double tmp = 0;
for (int i = 0; i < n1; i++)
{
tmp += array1[i];
if (i >= k)
{
tmp -= array1[i - k];
}
if (i >= k - 1)
{
double average = tmp / k;
printf("%2lld ", llrint(average));
}
return 0;
}
The program does not work because the problem is not understood.
I would like to know how to solve it.
add) Thank you for answer but the output required by the problem is as follows.
Input : 9 4 (n = 9, k = 3)
2 7 4 5 6 8 2 8 13
Output : 2 5 4 5 6 6 5 6 8
After Modifying your code
int main()
{
int i, n1, k;
int *array1, *array2;
scanf("%d", &n1);
array1 = (int *)malloc(sizeof(int)*n1);
scanf("%d", &k);
for (i = 0; i < n1; i++)
{
scanf("%d", &array1[i]);
}
double tmp = 0;
for (int i = 0; i < n1; i++)
{
tmp += array1[i];
// now tmp contains exactly k + 1 elements sum
// so subtract elements outside of k sized window(leftmost element)
if(i >= k) {
tmp -= array1[i - k];
}
if(i >= k - 1) {
double average = tmp / k;
printf("%lf\n", average);
}
}
return 0;
}

2d-arrays in bubble sorting

I'm trying to create a 2d-array in bubble sort, arranged 25 numbers 5 by 5 in ascending order
my inputs
Enter 25 integers:
Input No.[0][0]: 4
Input No.[0][1]: 5
Input No.[0][2]: 8
Input No.[0][3]: 9
Input No.[0][4]: 4
Input No.[1][0]: 2
Input No.[1][1]: 1
Input No.[1][2]: 0
Input No.[1][3]: 2
Input No.[1][4]: 4
Input No.[2][0]: 6
Input No.[2][1]: 7
Input No.[2][2]: 4
Input No.[2][3]: 5
Input No.[2][4]: 5
Input No.[3][0]: 4
Input No.[3][1]: 8
Input No.[3][2]: 9
Input No.[3][3]: 1
Input No.[3][4]: 2
Input No.[4][0]: 4
Input No.[4][1]: 5
Input No.[4][2]: 2
Input No.[4][3]: 1
Input No.[4][4]: 9
my output shows
Ascending:
4 4 5 8 9
0 1 2 2 4
4 5 5 6 7
1 2 4 8 9
1 2 4 5 9
as you can see its not in proper arranged, it only arranged the 5 numbers each lines not the whole numbers
can anybody help arranged my integers like this
Ascending:
0 1 1 1 2
2 2 2 4 4
4 4 4 4 5
5 5 5 6 7
8 8 9 9 9
this is my code so far
int main(){
int rows = 5, cols = 5;
int arr[rows][cols];
int i,j,k,swap;
printf("Enter 25 integers:\n");
for(i = 0; i < rows; i++){
for(j = 0; j < cols; j++){
printf("Input No.[%d][%d]: ", i+0,j+0);
scanf("%d", &arr[i][j]);
}
}
for(k = 0; k < rows; k++){
for(i = 0 ; i < cols; i++){
for(j = i + 1; j < cols; j++){
if(arr[k][i] > arr[k][j]){
swap = arr[k][i];
arr[k][i] = arr[k][j];
arr[k][j] = swap;
}
}
}
}
printf("Ascending:\n");
for( i = 0 ; i < rows; i++){
for( j = 0 ; j < cols; j++){
printf("%3d", arr[i][j]);
}
printf("\n");
}
getch();
}
Improving on Ahmad's answer, I would like to add the following code (for shorting the table in ascending order):
#include <stdio.h>
#define COL 5
#define ROW 6
int main()
{
int temp, t, i, j;
int arr[ROW][COL]={30,29,28,27,26,25,24,23,22,21,20,19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1};
for(t=1; t<(ROW*COL); t++)
{
for(i=0; i<ROW; i++)
{
for(j=0; j<COL-1; j++)
{
if (arr[i][j]>arr[i][j+1])
{
temp=arr[i][j];
arr[i][j]=arr[i][j+1];
arr[i][j+1]=temp;
}
}
}
for(i=0; i<ROW-1; i++)
{
if (arr[i][COL-1]>arr[i+1][0])
{
temp=arr[i][COL-1];
arr[i][COL-1]=arr[i+1][0];
arr[i+1][0]=temp;
}
}
}
for(i=0; i<ROW; i++)
{
printf("\n");
for(j=0; j<COL; j++)
printf("%3d", arr[i][j]);
}
return 0;
}
replace the input with your table and the definitions with the size of your given array and you're done.
output of the above when executed:
1 2 3 4 5
6 7 8 9 10
11 12 13 14 15
16 17 18 19 20
21 22 23 24 25
26 27 28 29 30
void twoDimBubbleSort(int** arr, int row, int col) {
for (int i = 0; i < (row * col); ++i) {
for (int j = 0; j < (row * col) - 1; ++j) {
int cr = j / col; // current row
int cc = j % col; // current column
int nr = (j + 1) / col; // next item row
int nc = (j + 1) % col; // next item column
if (arr[cr][cc] > arr[nr][nc])
swap(&arr[cr][cc], &arr[nr][nc]); // any way you want to swap variables
}
}
}
You don't necessarily need to create a 1D array, you can consider your 2D array is a 1D array and transform coordinates when you set/get them.
Consider a structure point with x and y, and ARR_LEN is 5.
int from2Dto1D(point p){ return p.x+ p.y*ARR_LEN;}
Point from1Dto2D(int i){ Point p; p.x = i%ARR_LEN; p.y=i/ARR_LEN; return p;}
Now you can use the normal bubble sorting algorithm with a 1D index on 2D squares array, you just need to convert your index into 2 Point and access/switch data using these Point. (2 because you need a Point with index and a Point with index+1
Put all the array elements from 2-D array to 1-D array then
sort that 1-D array and then put 1-D array in the matrix format
Try this code ....works according to the above given logic
#include<stdio.h>
int main(){
int arr[5][5],l=0;
int result[25],k=0,i,j,temp;
arr[0][0]= 4;
arr[0][1]= 5;
arr[0][2]= 8;
arr[0][3]= 9;
arr[0][4]= 4;
arr[1][0]= 2;
arr[1][1]= 1;
arr[1][2]= 0;
arr[1][3]= 2;
arr[1][4]= 4;
arr[2][0]= 6;
arr[2][1]= 7;
arr[2][2]= 4;
arr[2][3]= 5;
arr[2][4]= 5;
arr[3][0]= 4;
arr[3][1]= 8;
arr[3][2]= 9;
arr[3][3]= 1;
arr[3][4]= 2;
arr[4][0]= 4;
arr[4][1]= 5;
arr[4][2]= 2;
arr[4][3]= 1;
arr[4][4]= 9;
//convert 2 D array in 1 D array
for(i=0;i<5;i++){
printf("\n");
for(j=0;j<5;j++){
printf(" %d",arr[i][j]);
result[k++]=arr[i][j];
}
}
// sort 1 D array
for(i=0;i<25;i++){
for(j=0;j<24;j++){
if(result[j] > result[j+1]){
temp=result[j];
result[j]=result[j+1];
result[j+1]=temp;
}
}
}
/*
for(i=0;i<25;i++){
printf("\n%d",result[i]);
}*/
// convert 1 D array to 2 D array
i=0;
l=0;k=0;
while(i<25){
for(j=0;j<5;j++){
arr[k][j]=result[l];
l++;
}
k++;
i=i+5;
}
//Print matrix i.e 2D array
for(i=0;i<5;i++){
printf("\n");
for(j=0;j<5;j++){
printf(" %d",arr[i][j]);
}
}
}
This works !
#define COL 5
#define ROW 2
int main(){
int temp ;
int arr[2][5]= {2,15,26,14,12,18,1,2,3,4 };
int arr2[10] = {0};
int index = 0 ;
for(int t = 0 ; t<50 ; t++ ){
for (int i =0 ; i < ROW ; i++){
for( int j = 0; j < 5-1 ; j++){
if (arr[i][j] > arr[i][j+1]){
temp = arr[i][j];
arr[i][j] = arr[i][j+1];
arr[i][j+1] = temp;
}
}
//checking for
for( int k = 0 ; k < ROW-1 ; k++){
if (arr[k][COL-1] > arr[k+1][0]){
temp = arr[k][COL-1];
arr[k][COL-1] = arr[k+1][0];
arr[k+1][0] = temp ;
}
}
//---------
}
}
return 0 ;
}

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