Print the positive, negative, and all entries made using while loop - c

So I've tried to calculate the average of the positive and negative entries made in the while loop but I can't seem to enter any type of number into the console. So I need to enter numbers as long as it's not zero and add the positive numbers as well as negative numbers. I'm required to count how many positive and negative entries were entered. I need also to print the average of the positive and negatives entries.
Here is my code:
int num;
int positivenum = 0, negativenum = 0;
int cpositive = 0, cnegative = 0;
float average = 0;
printf("Enter a positive and negative integer:");
while (num!=0)
{
scanf("%d", &num);
if (num > 0){
positivenum += num;
cpositive++;
}
else if (num < 0){
negativenum += num;
cnegative++;
}

This is exactly when do while is judicious:
int num;
int positivenum = 0, negativenum = 0;
int cpositive = 0, cnegative = 0;
printf("Enter a positive and negative integer:");
do
{
scanf("%d", &num);
if (num > 0){
positivenum += num;
cpositive++;
}
else if (num < 0){
negativenum += num;
cnegative++;
}
} while (num!=0);
if (cpositive > 0)
printf("Average of positive numbers: %f\n", (double)positivenum / (double)cpositive);
if (cnegative > 0)
printf("Average of negative numbers: %f\n", (double)negativenum / (double)cnegative);

Changed the type of your counts from int to unsigned (negative counts doesn't make sense). Also moved the prompt inside the loop and and wrote a function to calculate the average:
#include <stdio.h>
void average(const char *what, int value, unsigned count) {
if(!count) return;
printf("average of %s numbers: %f\n", what, (float) value / count);
}
int main() {
int num;
int positivenum = 0, negativenum = 0;
unsigned cpositive = 0, cnegative = 0;
for(;;) {
printf("Enter a positive and negative integer: ");
scanf("%d", &num);
if(!num) break;
if(num < 0) {
negativenum += num;
cnegative++;
continue;
}
positivenum += num;
cpositive++;
}
average("positive", positivenum, cpositive);
average("negative", negativenum, cnegative);
}

#include <stdio.h>
int main() {
int num;
int positivenum = 0, negativenum = 0;
int cpositive = 0, cnegative = 0;
int range = 0;
int i = 0;
printf("Enter the range.\n");
scanf("%d", &range);
printf("Enter a positive and negative integer:\n");
do
{
scanf("%d", &num);
if (num > 0){
positivenum += num;
cpositive++;
}
else if (num < 0){
negativenum += num;
cnegative++;
}
i++;
} while ( (num!=0) && (i < range));
if (cpositive > 0)
printf("Average of positive numbers: %f\n", (float)positivenum / (float)cpositive);
if (cnegative > 0)
printf("Average of negative numbers: %f\n", (float)negativenum / (float)cnegative);
}
I have also added a range to break the loop.

Related

Finding MAX and MIN of random numbers

I'm writing a program where the user enters numbers and the program will find MAX and MIN and the position of these numbers. I want to give the user a choice for the program to fill in the numbers for him using rand().
It's working almost perfectly: the program will find the MAX number with the position but the problem occurs when printing MIN number with position -- it always prints number 8 and position 1.
Where is the problem?
Here is my code:
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
typedef struct elementposition {
int min;
int max;
int positionMax;
int positionMin;
} elementposition;
int main() {
struct elementposition minmax;
srand(time(NULL));
int a[500], i;
int c = sizeof(a) / sizeof(a[0]);
char y;
printf("How many numbers you want to enter: ");
scanf("%d", &c);
minmax.positionMax = minmax.positionMin = 0;
printf("Want to fill with random numbers? (Y/N)");
scanf(" %c", &y);
if (y == 'Y' || y == 'y') {
for (i = 0; i < c; i++) {
a[i] = rand() % 10000 + 1;
if (minmax.max < a[i]) {
minmax.max = a[i];
minmax.positionMax = i;
}
if (minmax.min > a[i]) {
minmax.min = a[i];
minmax.positionMin = i;
}
}
for (i = 0; i < c; i++) {
printf("Number #%d: %d\n", i + 1, a[i]);
}
} else {
printf("------------------------------------ \n");
printf("Enter (%d) numbers: \n", c);
scanf("%d", &a[0]);
minmax.max = minmax.min = a[0];
for (i = 1; i < c; i++) {
scanf("%d", &a[i]);
if (minmax.max < a[i]) {
minmax.max = a[i];
minmax.positionMax = i;
}
if (minmax.min > a[i]) {
minmax.min = a[i];
minmax.positionMin = i;
}
}
}
printf("\nMax number is %d, number position %d. \n", minmax.max, minmax.positionMax + 1);
printf("Min number is %d, number position %d. \n", minmax.min, minmax.positionMin + 1);
printf("------------------------------------ \n");
getch();
return 0;
}
You never initialize minmax.min nor minmax.max in the random case. The code has undefined behavior because it depends on uninitialized values which may be anything, including trap values on some rare architectures.
You should separate the input/generation phase from the scanning phase and use a common loop for that. Also check that c is positive and does not exceed the length of the array.
Here is a modified version:
#include <stdio.h>
#include <stdlib.h>
typedef struct elementposition {
int min;
int max;
int positionMax;
int positionMin;
} elementposition;
int main() {
struct elementposition minmax;
int a[500];
int i, count, len = sizeof(a) / sizeof(a[0]);
char y = 'y';
printf("How many numbers you want to enter: ");
if (scanf("%d", &count) != 1 || count < 1 || count > len) {
printf("invalid count\n");
return 1;
}
printf("Want to fill with random numbers? (Y/N)");
scanf(" %c", &y);
if (y == 'Y' || y == 'y') {
srand(time(NULL));
for (i = 0; i < count; i++) {
a[i] = rand() % 10000 + 1;
printf("Number #%d: %d\n", i + 1, a[i]);
}
} else {
printf("Enter (%d) numbers:\n", c);
for (i = 0; i < count; i++) {
if (scanf("%d", &a[i]) != 1) {
printf("invalid input\n");
return 1;
}
}
}
minmax.positionMax = minmax.positionMin = 0;
minmax.max = minmax.min = a[0];
for (i = 1; i < count; i++) {
if (minmax.max < a[i]) {
minmax.max = a[i];
minmax.positionMax = i;
}
if (minmax.min > a[i]) {
minmax.min = a[i];
minmax.positionMin = i;
}
}
printf("------------------------------------\n");
printf("Max number is %d, number position %d.\n", minmax.max, minmax.positionMax + 1);
printf("Min number is %d, number position %d.\n", minmax.min, minmax.positionMin + 1);
printf("------------------------------------\n");
getch();
return 0;
}
You use minmax.min and minmax.max before initializing them. Here the problem for finding the min is probably that the minmax.min happens to initialy contain the value 8 and that all the values are greater.
The common way is to initialize the min to the highest possible value and max to the lowest one. As you use int values:
struct elementposition minmax = { INT_MAX, INT_MIN };
should be enough.

C programming find min,max and sum without using recursion and arrays

I am trying to write a program that get bunch of numbers, n >= 5
The program asks from the user to enter n non-negative numbers and calculate min,max and the sum of the numbers.
In case the user enter negative numbers, the function asks to enter a positive number.
I have a problem with the first negative number, any clue what's wrong with the following code?
void main()
{
int x;
printf("Enter number:\n");
scanf("%d", &x);
if (x >= 5)
{
int max = 0, min, num1;
printf("Enter numbers: \n");
scanf("%d", &num1); //here was the error
min = num1;
int sum = num1;
for (int i = 1; i < x; i++)
{
scanf("%d", &num1);
while (num1 < 0)
{
{
printf("Enter again number: /n");
scanf("%d", &num1);
}
}
if (num1 > max)
max = num1;
else if (num1 < min)
min = num1;
sum += num1;
}
printf("The max number is %d, and the min is %d, and the sum is %d", max, min, sum);
}
else
printf("invalid number!");
}
output:
Enter number:
8
Enter numbers:
-8
7
6
9
10
6
7
6
The max number is 10, and the min is -8, and the sum is 43
check if min<0 assign new entered value of num1 to it.
for (int i = 1; i < x; i++)
{
scanf("%d", &num1);
if (min < 0)
min = num1;
while (num1 < 0){
//rest of the code}
}
I have a problem with the first negative number, any clue what's wrong with the following code?
Do not read first number with special code, which lacks a negative test. Simplify and read just like other numbers.
Simply start min,max with extremes.
#include <limits.h>
...
int max = INT_MIN;
int min = INT_MAX;
int sum = 0;
printf("Enter numbers: \n");
for (int i = 0; i < x; i++) { // start at 0
int num1;
scanf("%d", &num1);
while (num1 < 0) {
printf("Enter again number: /n");
scanf("%d", &num1);
}
if (num1 > max)
max = num1;
// else if (num1 < min)
if (num1 < min)
min = num1;
sum += num1;
}
printf("The max number is %d, and the min is %d, and the sum is %d",
max, min, sum);
you should put while after taking the input from the user to prevent any negative number also inside while there isn't need to put double cure prates
#include <stdio.h>
int main()
{
int x;
printf("Enter number:\n");
scanf("%d", &x);
if (x >= 5)
{
int max = 0, min, num1,sum;
printf("Enter numbers:\n");
sum = 0;
min = num1;
for (int i = 1; i<=x; i++)
{
scanf("%d",&num1);
while(num1<0)
{
printf("Enter again number: \n ");
scanf("%d", &num1);
}
if (num1 > max)
{ max = num1;}
if (num1<min)
{ min = num1;}
sum += num1;
}
printf("The max number is %d, and the min is %d, and the sum is %d", max, min, sum);
}
else
printf("invalid number!");
return 0;
}
````````````

I need help figuring out why is this not working. (C)

This is what i get This code needs to print out 2 maximum numbers, when -999 is entered the code needs to stop.
I tried every thing but most of the times i get the maximum number but not the second maximum number.
#include <stdio.h>
int main ()
{
int x = 0;
int max = 0;
int max2 = 0;
int y = 0;
int flag = 0;
do
{
printf("Enter the number -999 to stop: ");
scanf("%d", &x);
if (x != -999)
{
if (x > max)
{
max = x;
max2 = y;
}
printf("Enter the number -999 to stop: ");
scanf("%d", &y);
if (y != -999)
{
if (y > max)
{
max = y;
max2 = x;
}
}
else
{
flag = 1;
}
}
else
{
flag = 1;
}
}
while (flag == 0);
printf("The max number is: %d\n", max);
printf("The second max number is: %d\n", max2);
return 0;
}
#include <stdio.h>
int main ()
{
int x = 0;
int max = 0;
int max2 = 0;
int flag = 0;
do
{
printf("Enter the number -999 to stop: ");
scanf("%d", &x);
if (x != -999)
{ // bigger than max?
if (x > max)
{
// since the new max is x and the old max is bigger than max2
max2 = max;
max = x;
}
// bigger than max2?
else if (x > max2)
{
max2 = x;
}
}
else // exit loop
{
flag = 1;
}
}
while (flag == 0);
printf("The max number is: %d\n", max);
printf("The second max number is: %d\n", max2);
return 0;
}
There are more problems in your code.
You have unnecessary two inputs (x and y), then you wrongly assume, when x > max, then y contains second max, and when y > max then x contains second max.
Correct code should look like this:
int main()
{
int x = 0;
int max = 0;
int max2 = 0;
while (true)
{
printf("Enter the number (-999 to stop): ");
scanf("%d", &x);
if (x == -999)
{
break;
}
if (x > max)
{
max2 = max;
max = x;
}
else if (x > max2)
{
max2 = x;
}
}
printf("\n\nThe max number is: %d\n", max);
printf("The second max number is: %d\n", max2);
return 0;
}

Sum of prime factors

I am trying to show the sum of the prime factors of a given number and
I'm having difficulties displaying the prime factors in my output.
Sample Output:
Input number: 6
Factors are: 1 2 3
Sum of its factor: 1 +2 +3 =6
I am able to show the sum but I want to show the 1+2+3=6 like in the sample above where the factors are 1 2 3.
Can you help me correct my syntax to achieve this? Thanks in advance.
Here's my code:
#include <stdio.h>
int main() {
int i, j, num, isPrime, sum;
printf("Input number: ");
scanf("%d", &num);
printf("Factors are: ", num);
for (i = 1; i <= num; i++) {
if (num % i == 0) {
isPrime = 1;
for (j = 2; j <= i / 2; j++) {
if (i % j == 0) {
isPrime = 0;
break;
}
}
if (isPrime == 1) {
printf("%d ", i);
sum += i;
}
}
}
printf("\nSum of its factor : %d", sum);
return 0;
}
Your code actually has undefined behavior because sum is not initialized to 0. It produces the correct sum only by chance.
You can store the factors in an array, or even construct the expression as you go with sprintf. The maximum length of the expression is not very large as there can be at most 9 different prime factors (29!! > 232)
Here is a modified version:
#include <stdio.h>
int main() {
char expr[9 * 11 + 1];
int i, j, pos, num, isPrime, sum;
printf("Input number: ");
if (scanf("%d", &num) != 1)
return 1;
printf("Factors are: 1"); // always include 1
pos = 0;
expr[pos] = '\0';
sum = 1;
for (i = 2; i <= num; i++) {
if (num % i == 0) {
isPrime = 1;
for (j = 2; j * j <= i; j++) {
if (i % j == 0) {
isPrime = 0;
break;
}
}
if (isPrime == 1) {
pos += sprintf(expr + pos, "+%d", i);
printf(" %d", i);
sum += i;
}
}
}
printf("\nSum of its factors: 1%s = %d\n", expr, sum);
return 0;
}
Output:
Input number: 6
Factors are: 1 2 3
Sum of its factors: 1+2+3 = 6
Here is a more robust and much faster version that does not have undefined behavior for very large values of num:
#include <stdio.h>
int main() {
char expr[9 * 11 + 1];
int i, pos, num;
unsigned sum;
printf("Input number: ");
if (scanf("%i", &num) != 1)
return 1;
printf("Factors are: 1"); // always include 1
pos = 0;
expr[pos] = '\0';
sum = 1;
for (i = 2; num / i >= i; i++) {
if (num % i == 0) {
pos += sprintf(expr + pos, "+%d", i);
printf(" %d", i);
sum += i;
do { num /= i; } while (num % i == 0);
}
}
if (num != 1) {
pos += sprintf(expr + pos, "+%d", num);
printf(" %d", num);
sum += num;
}
printf("\nSum of its factors: 1%s = %u\n", expr, sum);
return 0;
}
Test:
Input number: 0x7fffffff
Factors are: 1 2147483647
Sum of its factors: 1+2147483647 = 2147483648
Since you want to print all the prime factors twice, you should do that in a way so that you can avoid duplicated code. Here is an idea:
#include <stdio.h>
/* Return the smallest prime that is smaller than or equal to n */
/* Assumes that the argument is greater than 1 */
int getFirst(int n)
{
int i;
for(i = 2; i <= n; i++)
if(n % i == 0)
return i;
}
int main()
{
int num, x, tmp, sum=0;
scanf("%d", &num);
tmp = num;
printf("Factors are: ");
while(1) {
x = getFirst(tmp);
printf("%d ", x);
if (x == tmp) /* If we are at the last prime */
break;
tmp /= x;
}
printf("\n");
printf("Sum of factors is: ");
tmp = num;
while(1) {
x = getFirst(tmp);
printf("%d ", x);
sum += x;
if(x == tmp) /* If we are at the last prime */
break;
printf("+ ");
tmp /= x;
}
printf("= %d\n", sum);
}
But as has been pointed out in the comments. 1 is not a prime, and that's why I excluded it.

Sum and get the average of the values in the array

Sum and get the average of the values in the array, and stop to ask a number when the sum exceeds 10,000.I need to clear it with an example of these conditions.
The language fit that need the example is in C
my code
```
#include <stdio.h>
int main()
{
int array[10];
int i, num, negative_sum = 0, positive_sum = 0;
float total = 0.0, average;
printf ("Enter the value of N \n");
scanf("%d", &num);
printf("Enter %d numbers (negative, positve and zero) \n", num);
for (i = 0; i < num; i++)
{
scanf("%d", &array[i]);
}
printf("Input array elements \n");
for (i = 0; i < num; i++)
{
printf("%+3d\n", array[i]);
}
for (i = 0; i < num; i++)
{
if (array[i] < 0)
{
negative_sum = negative_sum + array[i];
}
else if (array[i] > 0)
{
positive_sum = positive_sum + array[i];
}
else if (array[i] == 0)
{
;
}
total = total + array[i] ;
}
average = total / num;
printf("\n Sum of all negative numbers = %d\n", negative_sum);
printf("Sum of all positive numbers = %d\n", positive_sum);
printf("\n Average of all input numbers = %.2f\n", average);
}
```
Answer of your Question
#include <stdio.h>
int main()
{
int array[10];
int num, negative_sum = 0, positive_sum = 0,j;
static int i=0;
float total = 0.0, average;
label:
j=i;
printf ("Enter the value of N \n");
scanf("%d", &num);
printf("Enter %d numbers (negative, positve and zero) \n", num);
for (i; i < (j+num); i++)
{
scanf("%d", &array[i]);
}
i=j;
printf("Input array elements \n");
for (i; i < (j+num); i++)
{
printf("%d\n", array[i]);
}
i=j;
for (i; i < (j+num); i++)
{
if (array[i] < 0)
{
negative_sum = negative_sum + array[i];
}
else if (array[i] > 0)
{
positive_sum = positive_sum + array[i];
}
else if (array[i] == 0)
{
;
}
total = total + (float)array[i] ;
}
average = total / num;
printf("\n Sum of all negative numbers = %d\n", negative_sum);
printf("Sum of all positive numbers = %d\n", positive_sum);
printf("\n Average of all input numbers = %.2f\n", average);
if(total<10000)
{
printf("Total is less than 10000 and Now total is : %.2f\n",total);
goto label;
}}
it is the answer of your question.program will run when your total is exceed upto 10000.

Resources