To summarize my problem,
i want an array to return two array pointers. One of these pointer arrays must be float or double, this will give me the quotient operation. Another should be int, and that should give the remainder of the division.
For examle if i have two arrays as: int a[] = {3,6,9,12,16,18}, b[] = {2,3,3,4,4,4}; when i want to reach my pointers result should be like: Quotient is: {1.5,2,3,3,4,4.5} Remainder is: {1,0,0,0,0,2}
Here is my codes:
#include<stdio.h>
void div(int a[], int b[], float *quotient, int *remainder) {
float quo[6];
int remain[6];
for(int i = 0; i< 6 ; i++)
{
quo[i] = a[i] / (double)b[i];
remain[i] = a[i] % b[i];
*remainder = remain[i];
*quotient = quo[i];
*remainder++;
*quotient++;
}
// quotient = quo;
// remainder = remain;
}
int main() {
int a[] = {3,6,9,12,16,18}, b[] = {2,3,3,4,4,4};
float q;
int r;
div(a, b, &q, &r);
for(int i = 0; i< 6 ; i++)
{
printf("Quotient is: %.1f\nRemainder is: %d\n", q, r);
}
// printf("Quotient is: %.1f\nRemainder is: %d\n", *q, *r);
return 0;
}
You need to pass an array for the quotient and remainder into the divide function.
Than you can read the values after the function returns.
#include<stdio.h>
void div(int* a, int* b, float* quotient, int* remainder, int count) {
for (int i = 0; i < count; i++)
{
quotient[i] = a[i] / (double)b[i];
remainder[i] = a[i] % b[i];
}
}
int main() {
int a[] = { 3,6,9,12,16,18 }, b[] = { 2,3,3,4,4,4 };
#define LENGTH (sizeof(a) / sizeof(int))
float quotient[LENGTH];
int remainder[LENGTH];
div(a, b, quotient, remainder, LENGTH);
for (int i = 0; i < LENGTH; i++)
{
printf("Quotient is: %.1f\nRemainder is: %d\n", quotient[i], remainder[i]);
}
return 0;
}
Related
Calculating the sum of the first k numbers of the sequence a[0] = 1, a[k] = k*a[k-1] +1/k ( k = 1, 2, ... ).
UPD
There is still a problem with the recursive function ...What is the error?
#include <stdio.h>
#include <stdlib.h>
float m(float n){
float k=1;
float sum=k;
int i;
for (i=1; i<n;i++){
k = (i*k+1.0/i);
sum = sum+k;
}
return sum;
}
float Fn(float n)
{
if (n==0) {
return 1;}
return ((n*Fn(n-1)+1.0/n)+Fn(n-1));
}
int main(int argc, char *argv[]) {
float k;
printf("input k : ");
scanf("%f",&k);
printf("res %f \n",Fn(k));
return 0;
}
There were several issues in your code:
Integer division: 1/n = 0
There was a confusion between the term value Fn and the sum value
An iterative solution is simpler here than a recursive one
Here is a code, with both iterative and recursive implementations:
#include <stdio.h>
#include <stdlib.h>
float sum_fn(int n){
float Fk = 1;
float sum = Fk;
for (int i = 1; i <= n; i++){
Fk = i*Fk + 1.0/i;
sum += Fk;
}
return sum;
}
float sum_recursive(int n, float *sum){
if (n == 0) {
*sum += 1.0;
return 1.0;
}
float Fn = n * sum_recursive(n-1, sum) + 1.0/n;
*sum += Fn;
return Fn;
}
int main(int argc, char *argv[]) {
int k;
printf("input k : ");
scanf("%d", &k);
printf("k = %d\tsum = %f\n", k, sum_fn(k));
float sum = 0;
sum_recursive(k, &sum);
printf("k = %d\tsum = %f\n", k, sum);
return 0;
}
I'm comparing arrays here by elements value then storing the score in score[] array
I would like to know how to print all the score array using score = compareTriplets(a,b) if possible.
If not, what is the best approach to get the output?
#include<stdio.h>
int a[3];
int b[3];
int score[] = {0,0};
int *compareTriplets(int a[], int b[]);
int *compareTriplets(int a[], int b[])
{
int i;
for(i=0;i<3;i++)
{
if( a[i] > b[i])
{
score[0] += 1;
}
else if( b[i] > a[i])
{
score[1] += 1;
}
}
return score;
}
int main()
{
int k;
int score;
scanf("%d %d %d", &a[0], &a[1], &a[2]);
scanf("%d %d %d", &b[0], &b[1], &b[2]);
score = compareTriplets(a,b);
for(k=0;k<2;k++)
{
printf("%d",score[k]);
}
}
compareTriplets delivers a pointer to a int array.
Your score variable in your main method will therefore have to have the type int *. Meaning it is the pointer to the first int in the array.
#include<stdio.h>
int a[3];
int b[3];
int score[] = {0,0};
int *compareTriplets(int a[], int b[]);
int *compareTriplets(int a[], int b[])
{
int i;
for(i=0;i<3;i++)
{
if( a[i] > b[i])
{
score[0] += 1;
}
else if( b[i] > a[i])
{
score[1] += 1;
}
}
return score;
}
int main(int argc, char** argv)
{
a[0] = a[1] = a[2] = 1;
b[0] = b[1] = b[2] = 2;
int *score = compareTriplets(a,b);
printf("%d, %d\n", score[0], score[1]);
return 0;
}
To print it, we access the array elements by the [] operator.
However let me add, that having your score array be a global variable seems like the wrong decision here.
int *compareTriplets(const int a[], const int b[], int *score)
{
int i;
score[0] = 0; score[1] = 0;
for(i=0;i<3;i++)
{
if( a[i] > b[i])
{
score[0] += 1;
}
else if( b[i] > a[i])
{
score[1] += 1;
}
}
return score;
}
Usage:
int main(void)
{
int a[3] = {rand(), rand(), rand()};
int b[3] = {rand(), rand(), rand()};
int score[2];
compareTriplets(a,b,score);
printf("%d %d\n", score[0], score[1]);
}
or
struct score
{
int score[2];
};
struct score compareTriplets(const int a[], const int b[])
{
int i;
struct score sc = {0,0};
for(i=0;i<3;i++)
{
if( a[i] > b[i])
{
sc.score[0] += 1;
}
else if( b[i] > a[i])
{
sc.score[1] += 1;
}
}
return sc;
}
and usage"
int main(void)
{
int a[3] = {rand(), rand(), rand()};
int b[3] = {rand(), rand(), rand()};
struct score sc = compareTriplets(a,b);
printf("%d %d\n", sc.score[0], sc.score[1]);
}
The rest of my functions work fabulously, however the last function has my goat. The goal of this function is to use pointers to obtain the values of two different arrays and add those values to a third array. However, when I run the main method to make the function run, it pauses for a second and provides a wedge exit code that does not work.
I've tried removing the if((sizeof(*ptr1)) == (sizeof(*ptr2)){
---insert code here---
}
from the for loop, however, the problem seems to be just the for loop itself.
//===================================Broken Code========================================
#include <stdio.h>
#define MAXIMUM 1000
int sumArrays(int arr1[], int arr2[]);
int addArrays(int arr1[], int arr2[]);
int main()
{
int arrayOne[MAXIMUM];
int arrayTwo[MAXIMUM];
for(int i = 0; i <= MAXIMUM; i++)
arrayOne[i] = i;
printf("Arrayone %d\n", arrayOne);
for(int j = 0; j <= MAXIMUM; j++)
arrayTwo[j] = j;
printf("ArrayTwo %d\n", arrayTwo);
printf(" The sum of the arrays is : %d\n",sumArrays(arrayOne, arrayTwo));
printf("%d", addArrays(arrayOne, arrayTwo));
return 0;
}
int sumArrays(int arr1[],int arr2[]){
int *ptr_1;
int *ptr_2;
ptr_1 = &arr1[0];
ptr_2 = &arr2[0];
int sum;
for(int i = 0; i < MAXIMUM; i++){
sum += *ptr_1 + i;
sum += *ptr_2 + i;
}
return sum;
}
int addArrays(int arr1[],int arr2[]){
int *ptr1 = &arr1[0];
int *ptr2 = &arr2[0];
int sum = 0;
int i = 0;
int arr3[0];
if(sizeof(*ptr1) == sizeof(*ptr2)){
for(int i = 0; i < MAXIMUM; i++){
sum += *ptr1 +i;
sum += *ptr2 +i;
arr3[i] = sum;
}
}
printf("The value of array3 is %d", arr3);
}
The other function works perfectly, but the addArrays function does a wedge exit and doesn't cooperate.
I expect the addArrays function to take the elements from each array, add them together and assign them to the third array.
Thank you for your time.
UPDATE: WORKING CODE
#include <stdio.h>
#define MAXIMUM 1000
#define ARRAY_SZ(x) (sizeof(x) / sizeof((x)[0]))
int sumArrays(int arr1[], int arr2[], size_t len);
int addArrays(int arr1[], int arr2[], int arr3[], size_t len);
int main()
{
int arrayOne[MAXIMUM];
int arrayTwo[MAXIMUM];
int arrayThree[MAXIMUM];
for(int i = 0; i <= MAXIMUM; i++)
arrayOne[i] = i;
printf("Array One %d\n", ARRAY_SZ(arrayOne));
for(int j = 0; j <= MAXIMUM; j++)
arrayTwo[j] = j;
printf("Array Two %d\n", ARRAY_SZ(arrayTwo));
printf(" The sum of the arrays is : %d\n",sumArrays(arrayOne, arrayTwo, ARRAY_SZ(arrayOne)));
printf("%d", addArrays(arrayOne, arrayTwo, arrayThree, MAXIMUM));
return 0;
}
int sumArrays(int arr1[],int arr2[], size_t len){
int *ptr_1;
int *ptr_2;
ptr_1 = &arr1[0];
ptr_2 = &arr2[0];
int sum = 0 ;
for(int i = 0; i < len; i++){
sum += *ptr_1++;
sum += *ptr_2++;
}
return sum;
}
int addArrays(int arr1[],int arr2[], int result[], size_t len){
int *ptr1 = &arr1[0];
int *ptr2 = &arr2[0];
int *ptr3 = &result[0];
int sum = 0;
int sum2 = 0;
int i = 0;
for(int i = 0; i < MAXIMUM; i++){
sum = *ptr1 ++;
sum += *ptr2 ++;
result[i] = sum;
printf("The result of array 3 is %d\n", *ptr3++);
}
}
Here are some notes:
When you assign/pass/print the and array using the name of the array, you are actually passing the memory location of the first element in the array (a pointer).So when you write:
printf("Arrayone %d\n", arrayOne);
You will see the memory address of the first element of the array being printed. If you would like to print the entire array you will need to loop through it. In this case you would be printing 1000 integers which might be undesirable.
void printArray(int * array, size_t len)
{
while(len--)
{
printf("%d ", *array++);
}
}
To get the number of elements in an array you can do something like this:
sizeof(arrayOne) / sizeof(arrayOne[0])
and you can put it in a macro like this:
#define ARRAY_SZ(x) (sizeof(x) / sizeof((x)[0]))
and call it like this:
ARRAY_SZ(arrayOne);
You cannot get the array size if you are receiving an array in a function (it has decayed to a pointer), instead you should pass the array size to the function too. Here because you initialize the arrays with the size MAXIMUM we don't actually need to calculate the array size, but we can just to show it works.
If you want to return an array (like in addArrays()) you should create an empty array and pass it to the function, then the function can update the array with the result.
When looping through an array you never want to do array[maximum] because the array indices range from 0 to maximum - 1
#include <stdio.h>
#define MAXIMUM 1000
#define ARRAY_SZ(x) (sizeof(x) / sizeof((x)[0]))
int sumArrays(int arr1[], int arr2[]);
int addArrays(int arr1[], int arr2[]);
int main()
{
int arrayOne[MAXIMUM];
int arrayTwo[MAXIMUM];
int arrayThree[MAXIMUM];
for(int i = 0; i < MAXIMUM; i++)
arrayOne[i] = i;
printf("Array one size %d\n", ARRAY_SZ(arrayOne));
for(int j = 0; j < MAXIMUM; j++)
arrayTwo[j] = j;
printf("Array Two size %d\n", ARRAY_SZ(arrayTwo));
printf(" The sum of the arrays is : %d\n",sumArrays(arrayOne, arrayTwo, ARRAY_SZ(arrayOne)));
addArrays(arrayOne, arrayTwo, arrayThree, MAXIMUM);
return 0;
}
int sumArrays(int arr1[],int arr2[], size_t len)
{
int *ptr_1;
int *ptr_2;
ptr_1 = &arr1[0];
ptr_2 = &arr2[0];
int sum;
for(int i = 0; i < len; i++){
sum += *ptr_1 + i;
sum += *ptr_2 + i;
}
return sum;
}
void addArrays(int arr1[], int arr2[], int result[], size_t len){
int *ptr1 = arr1;
int *ptr2 = arr2;
int sum = 0;
int i = 0;
for(int i = 0; i < len; i++){
sum = *ptr1 +i;
sum += *ptr2 +i;
result[i] = sum;
}
}
I have to use:
float average(const int tab[], int size);
float stdDev(const int tab[], int size);
to printf average and stdDev in C.
I have problem with average and i think with const int.
When i add const int tab[101] i have error with a1;
So how can i make it work with const int (if i can).
And if it is anything wrong with this code.
Any help will be helpful.
#include<stdio.h>
#include<math.h>
float average(const int tab[], int size);
float stdDev(const int tab[], int size);
int main()
{
float ave, std;
int a1;
int j;
int tab[101];
printf("Podaj liczby: ");
for(j=0; j<=99; j++)
{
a1 = scanf("%d", &tab[j]);
if(a1<1)
{
printf("Incorrect input");
return 1;
}
if(tab[0]==0)
{
printf("not enough data available");
return 2;
}
if(tab[j]==0)
{
break;
}
}
ave = average(tab, j);
printf("%.2f\n", ave);
std = stdDev(tab, j);
printf("%.2f", std);
return 0;
}
float average(const int tab[], int size)
{
int i;
float y=0, x;
if(size<=0)
{
return -1;
}
for(i=0; i<size; i++)
{
x = x + tab[i];
}
y = x/size;
return y;
}
float stdDev(const int tab[], int size)
{
int i;
float y, z, z1, z2=0, z3=0;
if(size<=0)
{
return -1;
}
y = average(tab, size);
for(i=0; i<size; i++)
{
z = tab[i] - y;
z1 = pow(z, 2);
z2 = z2 + z1;
z=0;
z1=0;
}
z3 = sqrt(z2/size);
return z3;
}
You define the variable x in average here:
float y=0, x;
without giving it a value. Then here:
x = x + tab[i];
you are reading its value without setting it anywhere beforehand. Because you never gave x a value, its value will be indeterminate and reading it will cause undefined behavior, which means that your program could e.g. print garbage output.
Always initialize your variables:
float y=0, x=0;
I am writing a program to add two large numbers in C.
My integer array result holds the sum of the two numbers (which were also stored in arrays).
For example, if the result array is [0,0,3,2] (actual array size is 20)
If 32 is my actual result, how can I display the contents of the result array without the leading zeros ?
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define BASE 10
void align(int A[],int n);
void add(int A[],int B[], int C[]);
void Invert(int* a, int n);
int main(int argc, char** argv){
char input1[20];
char input2[20];
int size = 20;
int a;
int b;
int num1[20];
int num2[20];
int result[20];
int length1 = strlen(argv[1]);
int length2 = strlen(argv[2]);
int i = 0;
for (i=0;i<length1;i++){
input1[i] = argv[1][i];
}
for (i=0;i<length2;i++){
input2[i] = argv[2][i];
}
a=atoi(input1);
b=atoi(input2);
align(num1,a);
align(num2,b);
add(num1,num2,result);
Invert(result,size);
for (i=0;i<20;i++){
printf("%d",result[i]);
}
return 0;
}
void align (int A[], int n){
int i = 0;
while (n) {
A[i++] = n % BASE;
n /= BASE;
}
while (i < 20) A[i++] = 0;
}
void add (int A[], int B[], int C[]) {
int i, carry, sum;
carry = 0;
for (i=0; i<20; i++) {
sum = A[i] + B[i] + carry;
if (sum >= BASE) {
carry = 1;
sum -= BASE;
} else
carry = 0;
C[i] = sum;
}
if (carry) printf ("overflow in addition!\n");
}
void Invert(int* a, int n)
{
int i;
int b;
for(i=0; i<n/2; i++){
b = a[i];
a[i] = a[n-i-1];
a[n-i-1] = b;
}
}
`
To get the actual digits (I assume that each digit is stored as a byte in an array of 20 bytes, lowest digit at highest index), you do something like this:
int i;
int size = sizeof(thearray) / sizeof(thearray[0]);
/* find first non-0 byte, starting at the highest "digit" */
for (i = 0; i < size - 1; ++i)
if (thearray[i] != 0)
break;
/* output every byte as character */
for (; i < size; i++)
printf("%c", thearray[i] + '0'); /* 0 --> '0', 1 --> '1', etc. */
printf("\n");
You can do this by below code:-
int flag=1;
for(i=0;i<20;i++)
{
if(flag==1&&array[i]!=0)
flag=0;
if(flag!=1)
{
printf("%d",array[i]);
}
}
This will remove all leading zeros.
I propose a solution by using the pointer. The situation where only zero is stored in the array is also handled. I'm more comfortable with the pointer.
int test[20] = {0,0,0,0,1,2,3,4,5,6,7,8,9,0,0,1,2,3,4,5};
int test_bis[20] = {0};
int * ptr_test = test_bis;
int ii = 0;
while( *(ptr_test)== 0 && ii < 20 ) {
ptr_test++;
ii++;
}
if( ii < 20)
do {
printf("%d",*(ptr_test));
ptr_test++;
} while (++ii < 20);
else
printf("0");
Thats for integer array you can modify it accordingly.
for(i=0;i<20;i++){
if(flag==1&&array[i]==0)
{
// just skips until first nonzero
}
else if(flag==1&&array[i]!=0){
flag=0; // when first nonzero comes set flag to 0 and print it
printf("%d",array[i]);
}
else {
printf("%d",array[i]); // after first nonzero simply print it
}
}