Code:
#include <stdio.h>
#include <stdlib.h>
// mat1
#define col_size1 3
#define row_size1 2
// mat2
#define col_size2 4
#define row_size2 3
// struct of i,j,arr[i][j]
typedef struct{
int i_index;
int j_index;
int value;
}index_s;
// struct of index_s linked list Node
typedef struct node_s{
index_s data;
struct node_s* next;
}node_s;
// struct of int list
typedef struct int_list_s{
int data;
struct int_list_s* next;
}int_list_s;
// print_array
void print_array(unsigned int* arr, int size){
int i;
printf("\nprint_array:\n");
for(i=0; i<size; i++){
printf("arr[%d] = %u\n", i, *(arr+i));
}
}
// free_matrix
void free_matrix(int** c, int n){
int i;
for(i=0; i<n; i++){
free(c[i]);
}
free(c);
}
// alloc_matrix
int** alloc_matrix(int rows, int cols){
int** c;
int i;
int j;
c = (int**)calloc(rows,sizeof(int*));
if(!c)
return NULL;
for(i=0; i<rows; i++){
c[i] = (int*)calloc(cols,sizeof(int));
if(!c[i]){
free_matrix(c,i);
return NULL;
}
for(j=0; j<cols; j++){
printf("arr[%d][%d]= ",i,j);
scanf("%d",&c[i][j]);
}
}
return c;
}
// print_din_matrix
void print_din_matrix(int** a, int rows, int cols){
int i,j;
for(i=0; i<rows; i++){
for(j=0; j<cols; j++){
printf("%d\t",a[i][j]);
}
printf("\n");
}
}
// node_s* push
node_s* push(node_s* headRef, index_s data){
node_s* newNode = malloc(sizeof(node_s));
newNode->data = data;
newNode->next = NULL;
if(headRef != NULL){
newNode->next = headRef;
}
headRef = newNode;
return headRef;
}
// print node_s list
void print_list(node_s* headRef){
while(headRef != NULL){
printf("i=%d\t j=%d\t value=%d\t\n", (*headRef).data.i_index,(*headRef).data.j_index,(*headRef).data.value);
headRef = headRef->next;
}
printf("\n");
}
// int push
int_list_s* int_push(int_list_s** headRef, int data){
int_list_s* newNode = malloc(sizeof(int_list_s));
newNode->data = data;
newNode->next = NULL;
if(*headRef == NULL){
*headRef = newNode;
return *headRef;
}
if((*headRef)->next == NULL){
(*headRef)->next = newNode;
}
else{
int_list_s* current = *headRef;
while(current->next != NULL){
current = current->next;
}
current->next = newNode;
}
return *headRef;
}
// print int list
void print_int_list(int_list_s* headRef){
int i = 1;
while(headRef != NULL){
printf("node %d = %d\n", i, headRef->data);
headRef = headRef->next;
i++;
}
}
// free linked_list
void free_int_list(int_list_s* headRef){
int_list_s* temp;
while(headRef != NULL){
temp = headRef;
headRef = headRef->next;
free(temp);
}
}
// taks 1
unsigned int* powerArray(int power){
unsigned int* p;
int i=1;
p = (unsigned int*)malloc(power*(sizeof(unsigned int)));
*p = 1;
for(i; i<power; i++){
*(p+i) = *(p+i-1)*2;
}
return p;
}
void first_main(){
unsigned int* p;
int power;
printf("Enter power: ");
scanf("%d", &power);
p = powerArray(power);
print_array(p, power);
}
// task 2
int** matrix_mul(int mat1[row_size1][col_size1], int mat2[row_size2][col_size2]){
int i = 0;
int j = 0;
int k = 0;
int sum = 0;
int** mat = (int**)malloc(row_size1 * sizeof(int*));
for(i; i<row_size1; i++){
mat[i] = (int*)malloc(col_size2 * sizeof(int));
}
for(i=0; i<row_size1; i++){
for(j=0; j<col_size2; j++){
for(k=0; k<col_size1; k++){
sum += mat1[i][k] * mat2[k][j];
}
mat[i][j] = sum;
sum = 0;
}
}
return mat;
}
void second_main(){
int mat1[row_size1][col_size1] = {{4,1,2},{6,0,3}};
int mat2[row_size2][col_size2] = {{5,7,2,9},{8,3,4,0},{6,1,2,7}};
int** arr;
arr = matrix_mul(mat1, mat2);
print_din_matrix(arr, row_size1, col_size2);
}
// task 3
int index_sum(int** arr, int rows, int cols, index_s** ans_arr, node_s** headRef){
int i;
int j;
int ans = 0;
int arr_i = 0;
for(i=0; i<rows; i++){
for(j=0; j<cols; j++){
if ((i+j) == arr[i][j]){
ans++;
}
}
}
*ans_arr = (index_s*)malloc(ans*sizeof(index_s));
for(i=0; i<rows; i++){
for(j=0; j<cols; j++){
if((i+j) == arr[i][j]){
(*ans_arr)[arr_i].i_index = i;
(*ans_arr)[arr_i].j_index = j;
(*ans_arr)[arr_i].value = arr[i][j];
arr_i++;
}
}
}
for(i=0; i<ans; i++){
*headRef = push(*headRef, (*ans_arr)[i]);
printf("\n");
}
return ans;
}
void third_main(){
int** arr;
index_s* ans_arr;
int rows, cols;
int num_of_sums;
node_s* head = NULL;
printf("Enter number of rows: ");
scanf("%d",&rows);
printf("Enter number of cols: ");
scanf("%d",&cols);
arr = alloc_matrix(rows, cols);
num_of_sums = index_sum(arr, rows, cols, &ans_arr, &head);
int i;
printf("Array print:\n");
for(i=0; i<num_of_sums; i++){
printf("i=%d\t j=%d\t value=%d\n", (ans_arr)[i].i_index, (ans_arr)[i].j_index, (ans_arr)[i].value);
}
printf("\n\nLinked list print:\n");
print_list(head);
printf("\nThe function returns:\nAns = %d\n", num_of_sums);
}
// task 4
int_list_s* del_odd(int_list_s** headRef){
int i;
int_list_s* temp = NULL;
int_list_s* previous = NULL;
if(*headRef == NULL){
return NULL;
}
if((*headRef)->data % 2 != 0){
temp = int_push(&temp, (*headRef)->data);
headRef = &((*headRef)->next);
}
while((*headRef)->next != NULL){
if((*headRef)->data % 2 == 0){
*headRef = (*headRef)->next;
}
else{
temp = int_push(&temp, (*headRef)->data);
printf("\n%d\n",temp->data);
previous = (*headRef)->next;
(*headRef)->next = previous->next;
}
}
return temp;
}
void fourth_main(){
int_list_s* head = NULL;
int_list_s* odd_list_head;
int data;
int list_size;
int i;
printf("Please enter the size of the list: ");
scanf("%d", &list_size);
for(i=0; i<list_size; i++){
printf("Enter node #%d: ", i);
scanf("%d",&data);
head = int_push(&head, data);
}
if(list_size == 0 ){
printf("The list is empty\n");
return;
}
print_int_list(head);
odd_list_head = del_odd(&head);
printf("\nOdd_list_head:\n");
print_int_list(odd_list_head);
printf("\nhead:\n");
print_int_list(head);
}
int main(){
int choice;
while(1){
printf("# Please select the exercise (1-5, 0 to exit): ");
scanf("%d",&choice);
if (choice == 0){
printf("Good bye\n");
return 0;
}
switch (choice) {
case 1:
first_main();
printf("\n");
break;
case 2:
second_main();
printf("\n");
break;
case 3:
third_main();
printf("\n");
break;
case 4:
fourth_main();
printf("\n");
break;
}
}
}
I have the function " int_list_s* del_odd(int_list_s** headRef) " that should delete all the odd numbers from the linked list (head) by reference and create new linked list ( odd_list_head ) with the numbers that i deleted. I can't figure what I'm doing wrong. 
problem in deleting and node from linked list
