use pointer for dynamic memory allocation

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Krishna Vedala 2020-04-23 20:08:15 -04:00
parent 2bd049c73a
commit bf1c367a62
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6 changed files with 154 additions and 122 deletions

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@ -1,49 +1,53 @@
//Fibonacci Series using Dynamic Programming //Fibonacci Series using Dynamic Programming
/* Author: Moinak Banerjee(moinak878) /* Author: Moinak Banerjee(moinak878)
Date : 1 October ,2019 Date : 1 October ,2019
*/ */
#include<stdio.h> #include <stdio.h>
#include<stdlib.h> #include <stdlib.h>
int fib(int n) int fib(int n)
{ {
//Out of Range checking //Out of Range checking
if(n<0){ if (n < 0)
{
printf("\nNo Such term !\n"); printf("\nNo Such term !\n");
exit(0); exit(0);
} }
//declaring array to store fibonacci numbers -- memoization //declaring array to store fibonacci numbers -- memoization
int f[n+2]; // one extra to handle edge case, n = 0 int *f = (int *)malloc((n + 2) * sizeof(int)); // one extra to handle edge case, n = 0
int i; int i;
/* let 0th and 1st number of the series be 0 and 1*/ /* let 0th and 1st number of the series be 0 and 1*/
f[0] = 0; f[0] = 0;
f[1] = 1; f[1] = 1;
for (i = 2; i <= n; i++) for (i = 2; i <= n; i++)
{ {
// Adding the previous 2 terms to make the 3rd term // Adding the previous 2 terms to make the 3rd term
f[i] = f[i-1] + f[i-2]; f[i] = f[i - 1] + f[i - 2];
} }
return f[n]; int out = f[n];
} free(f);
return out;
}
int main(int argc, char *argv[]) int main(int argc, char *argv[])
{ {
int number; int number;
//Asks for the number/position of term in Fibonnacci sequence //Asks for the number/position of term in Fibonnacci sequence
if (argc == 2) if (argc == 2)
number = atoi(argv[1]); number = atoi(argv[1]);
else { else
{
printf("Enter the value of n(n starts from 0 ): "); printf("Enter the value of n(n starts from 0 ): ");
scanf("%d", &number); scanf("%d", &number);
} }
printf("The nth term is : %d \n", fib(number)); printf("The nth term is : %d \n", fib(number));
return 0; return 0;
} }

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@ -7,7 +7,7 @@
int main(int argc, char **argv) int main(int argc, char **argv)
{ {
int a[MAX_LEN], n = 10, i, j, temp, sum = 0; int *a, n = 10, i, j, temp, sum = 0;
float mean; float mean;
if (argc == 2) if (argc == 2)
@ -18,6 +18,7 @@ int main(int argc, char **argv)
fprintf(stderr, "Maximum %d!\n", MAX_LEN); fprintf(stderr, "Maximum %d!\n", MAX_LEN);
return 1; return 1;
} }
a = (int *)malloc(n * sizeof(int));
} }
printf("Random Numbers Generated are : "); printf("Random Numbers Generated are : ");
@ -35,5 +36,6 @@ int main(int argc, char **argv)
printf("\nMean :"); printf("\nMean :");
printf("%f", mean); printf("%f", mean);
free(a);
return 0; return 0;
} }

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@ -1,4 +1,5 @@
#include <stdio.h> #include <stdio.h>
#include <stdlib.h>
int linearsearch(int *arr, int size, int val) int linearsearch(int *arr, int size, int val)
{ {
@ -17,7 +18,7 @@ int main()
printf("Enter the size of the array:\n"); printf("Enter the size of the array:\n");
scanf("%d", &n); //Taking input for the size of Array scanf("%d", &n); //Taking input for the size of Array
int a[n]; int *a = (int *)malloc(n * sizeof(int));
printf("Enter the contents for an array of size %d:\n", n); printf("Enter the contents for an array of size %d:\n", n);
for (i = 0; i < n; i++) for (i = 0; i < n; i++)
scanf("%d", &a[i]); // accepts the values of array elements until the loop terminates// scanf("%d", &a[i]); // accepts the values of array elements until the loop terminates//
@ -28,5 +29,7 @@ int main()
printf("Value %d is in the array.\n", v); printf("Value %d is in the array.\n", v);
else else
printf("Value %d is not in the array.\n", v); printf("Value %d is not in the array.\n", v);
free(a);
return 0; return 0;
} }

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@ -3,15 +3,16 @@
#include <stdlib.h> #include <stdlib.h>
/*Displays the array, passed to this method*/ /*Displays the array, passed to this method*/
void display(int arr[], int n){ void display(int *arr, int n)
{
int i;
for(i = 0; i < n; i++){ int i;
printf("%d ", arr[i]); for (i = 0; i < n; i++)
} {
printf("%d ", arr[i]);
printf("\n"); }
printf("\n");
} }
/*This is where the sorting of the array takes place /*This is where the sorting of the array takes place
@ -22,54 +23,63 @@ void bead_sort(int *a, int len)
{ {
int i, j, max, sum; int i, j, max, sum;
unsigned char *beads; unsigned char *beads;
# define BEAD(i, j) beads[i * max + j] #define BEAD(i, j) beads[i * max + j]
for (i = 1, max = a[0]; i < len; i++) for (i = 1, max = a[0]; i < len; i++)
if (a[i] > max) max = a[i]; if (a[i] > max)
max = a[i];
beads = calloc(1, max * len); beads = calloc(1, max * len);
/* mark the beads */ /* mark the beads */
for (i = 0; i < len; i++) for (i = 0; i < len; i++)
for (j = 0; j < a[i]; j++) for (j = 0; j < a[i]; j++)
BEAD(i, j) = 1; BEAD(i, j) = 1;
for (j = 0; j < max; j++) { for (j = 0; j < max; j++)
{
/* count how many beads are on each post */ /* count how many beads are on each post */
for (sum = i = 0; i < len; i++) { for (sum = i = 0; i < len; i++)
{
sum += BEAD(i, j); sum += BEAD(i, j);
BEAD(i, j) = 0; BEAD(i, j) = 0;
} }
/* mark bottom sum beads */ /* mark bottom sum beads */
for (i = len - sum; i < len; i++) BEAD(i, j) = 1; for (i = len - sum; i < len; i++)
BEAD(i, j) = 1;
} }
for (i = 0; i < len; i++) { for (i = 0; i < len; i++)
for (j = 0; j < max && BEAD(i, j); j++); {
for (j = 0; j < max && BEAD(i, j); j++)
;
a[i] = j; a[i] = j;
} }
free(beads); free(beads);
} }
int main(int argc, const char * argv[]) { int main(int argc, const char *argv[])
int n; {
printf("Enter size of array:\n"); int n;
scanf("%d", &n); // E.g. 8 1 2 3 printf("Enter size of array:\n");
scanf("%d", &n); // E.g. 8 1 2 3
printf("Enter the elements of the array\n");
int i; printf("Enter the elements of the array\n");
int arr[n]; int i;
for(i = 0; i < n; i++){ int *arr = (int *)malloc(n * sizeof(int));
scanf("%d", &arr[i] ); for (i = 0; i < n; i++)
} {
scanf("%d", &arr[i]);
printf("Original array: "); }
display(arr, n);
printf("Original array: ");
bead_sort(arr, n); display(arr, n);
printf("Sorted array: "); bead_sort(arr, n);
display(arr, n);
printf("Sorted array: ");
return 0; display(arr, n);
free(arr);
return 0;
} }

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@ -1,62 +1,70 @@
//sorting of array list using bubble sort //sorting of array list using bubble sort
#include <stdio.h> #include <stdio.h>
#include <stdlib.h>
/*Displays the array, passed to this method*/ /*Displays the array, passed to this method*/
void display(int arr[], int n){ void display(int *arr, int n)
{
int i; int i;
for(i = 0; i < n; i++){ for (i = 0; i < n; i++)
{
printf("%d ", arr[i]); printf("%d ", arr[i]);
} }
printf("\n"); printf("\n");
} }
/*Swap function to swap two values*/ /*Swap function to swap two values*/
void swap(int *first, int *second){ void swap(int *first, int *second)
{
int temp = *first; int temp = *first;
*first = *second; *first = *second;
*second = temp; *second = temp;
} }
/*This is where the sorting of the array takes place /*This is where the sorting of the array takes place
arr[] --- Array to be sorted arr[] --- Array to be sorted
size --- Array Size size --- Array Size
*/ */
void bubbleSort(int arr[], int size){ void bubbleSort(int *arr, int size)
{
for(int i=0; i<size-1; i++) {
for(int j=0; j<size-1-i; j++) { for (int i = 0; i < size - 1; i++)
if(arr[j]>arr[j+1]) { {
swap(&arr[j], &arr[j+1]); for (int j = 0; j < size - 1 - i; j++)
{
if (arr[j] > arr[j + 1])
{
swap(&arr[j], &arr[j + 1]);
} }
} }
} }
} }
int main(int argc, const char * argv[]) { int main(int argc, const char *argv[])
{
int n; int n;
printf("Enter size of array:\n"); printf("Enter size of array:\n");
scanf("%d", &n); // E.g. 8 scanf("%d", &n); // E.g. 8
printf("Enter the elements of the array\n"); printf("Enter the elements of the array\n");
int i; int i;
int arr[n]; int *arr = (int *)malloc(n * sizeof(int));
for(i = 0; i < n; i++){ for (i = 0; i < n; i++)
scanf("%d", &arr[i] ); {
scanf("%d", &arr[i]);
} }
printf("Original array: "); printf("Original array: ");
display(arr, n); // Original array : 10 11 9 8 4 7 3 8 display(arr, n); // Original array : 10 11 9 8 4 7 3 8
bubbleSort(arr, n); bubbleSort(arr, n);
printf("Sorted array: "); printf("Sorted array: ");
display(arr, n); // Sorted array : 3 4 7 8 8 9 10 11 display(arr, n); // Sorted array : 3 4 7 8 8 9 10 11
free(arr);
return 0; return 0;
} }

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@ -3,35 +3,37 @@
#include <stdlib.h> #include <stdlib.h>
// Displays the array, passed to this method // Displays the array, passed to this method
void display(int arr[], int n){ void display(int *arr, int n)
{
int i; int i;
for(i = 0; i < n; i++){ for (i = 0; i < n; i++)
{
printf("%d ", arr[i]); printf("%d ", arr[i]);
} }
printf("\n"); printf("\n");
} }
// Swap function to swap two values // Swap function to swap two values
void swap(int *first, int *second){ void swap(int *first, int *second)
{
int temp = *first; int temp = *first;
*first = *second; *first = *second;
*second = temp; *second = temp;
} }
// Function sort the array using Cycle sort // Function sort the array using Cycle sort
void cycleSort(int arr[], int n) void cycleSort(int *arr, int n)
{ {
// count number of memory writes // count number of memory writes
int writes = 0; int writes = 0;
// traverse array elements and put it to on // traverse array elements and put it to on
// the right place // the right place
for (int cycle_start = 0; cycle_start <= n - 2; cycle_start++) { for (int cycle_start = 0; cycle_start <= n - 2; cycle_start++)
{
// initialize item as starting point // initialize item as starting point
int item = arr[cycle_start]; int item = arr[cycle_start];
@ -51,13 +53,15 @@ void cycleSort(int arr[], int n)
pos += 1; pos += 1;
// put the item to it's right position // put the item to it's right position
if (pos != cycle_start) { if (pos != cycle_start)
{
swap(&item, &arr[pos]); swap(&item, &arr[pos]);
writes++; writes++;
} }
// Rotate rest of the cycle // Rotate rest of the cycle
while (pos != cycle_start) { while (pos != cycle_start)
{
pos = cycle_start; pos = cycle_start;
// Find position where we put the element // Find position where we put the element
@ -70,29 +74,29 @@ void cycleSort(int arr[], int n)
pos += 1; pos += 1;
// put the item to it's right position // put the item to it's right position
if (item != arr[pos]) { if (item != arr[pos])
{
swap(&item, &arr[pos]); swap(&item, &arr[pos]);
writes++; writes++;
} }
} }
} }
} }
// Driver program to test above function // Driver program to test above function
int main() int main()
{ {
int n; // Size of array elements int n; // Size of array elements
printf("Enter size of array:\n"); printf("Enter size of array:\n");
scanf("%d", &n); // E.g. 8 scanf("%d", &n); // E.g. 8
printf("Enter the elements of the array\n"); printf("Enter the elements of the array\n");
int i; int i;
int arr[n]; int *arr = (int *)malloc(n * sizeof(int));
for(i = 0; i < n; i++){ for (i = 0; i < n; i++)
scanf("%d", &arr[i] ); {
scanf("%d", &arr[i]);
} }
printf("Original array: "); printf("Original array: ");
@ -102,5 +106,6 @@ int main()
printf("Sorted array: "); printf("Sorted array: ");
display(arr, n); display(arr, n);
free(arr);
return 0; return 0;
} }