I wrote this program, which returns the biggest integer inserted by the user. Now, I would like the program to return the 2nd biggest integer. I created a new variable (called "status"), which is supposed to increment 1 unit every time the cycle repeats. Then, after the break condition happens, I would step back 1 unit in status variable, in order to retrieve the 2nd biggest number. I would like to follow this line of thought (if it is reliable in C) and I ask you fellows what is wrong with my current implementation.
#include <stdio.h>
int main()
{
int x, tmp=0, status=0, bigger;
printf("Insert numbers:\n");
do{
status+=1;
scanf("%d", &x);
if (tmp>=x)
bigger=tmp;
else {
bigger=x;
tmp=x;
}
}while (x!=0);
status-=1;
printf("The second biggest number is %d.\n", bigger);
return 0;
}
If you need only two biggest integers, you can just save them in each iteration, such that you have the max and max2 values:
#include <stdio.h>
int main()
{
int x, max=0, max2=0;
printf("Insert numbers:\n");
do {
scanf("%d", &x);
if (x > max) {
max2 = max; // Save the previous max, as the second largest value
max = x ; // Save the new max
}
else if (x > max2) {
max2 = x; // The input is not max, but greater than second max
}
}while (x!=0);
printf("The second biggest number is %d.\n", max2);
return 0;
}
The status in your code is just a counter. To solve your problem :
Use an array to store all the data.
Make a variable and test it if it is different than the biggest and bigger than all other entries
try this :
int main()
{
int x, status=0, bigger=0, secondbigger=0, Array[50];
while(true){
scanf("%d",&x)
if(x==0)break;
Array[status]=x;
status++;
}
for(i=0;i<status-1;i++){
if(Array[i]>bigger) bigger=Array[i];
}
for(i=0;i<status-1;i++){
if(Array[i]>secondbigger && Array[i]!=bigger) secondbigger=Array[i];
}
printf("The second biggest number is %d.\n", secondbigger);
return 0;
}
Related
#include <stdio.h>
int even_numbers_sum(){
int d;
for(d=0;d<=100;d++){
if(d%2==0){
printf("\n this is even number loop %d",d);
}
}
int sum;
sum=sum+d;
printf("\n the value of total sum of the loop %d",sum);
return sum;
}
int main(){
even_numbers_sum();
}
my main aim is to calculate the sum of all the elemets of for loop i took a for loop and described its value and put a equation (if) to pass anynumber if its only even other wise it will not work and i have to add all those even number till 100 how do i do it
Initialised sum to 0 at the beginning. Changed the return type of the function to void as int was unnecessary. Sum has to be incremented in the if statement.
#include <stdio.h>
void even_numbers_sum(){
int d;
int sum=0;
for(d=0;d<=100;d++){
if(d%2==0){
printf("\n this is even number loop %d",d);
sum=sum+d;
}
}
printf("\n the value of total sum of the loop %d",sum);
}
int main(){
even_numbers_sum();
}
look the following code. I've written this code for any number if you want to change the upper bound instead of 100 , you just have to pass the integer to the function i.e. if you want to get the sum of all even integers from 0 to 100, you have to pass 100 while calling the function.
#include <stdio.h>
void even_numbers_sum(int i){
int d;
int sum=0;
for(d=0;d<=i;d+=2){
printf("\n this is even number loop %d",d);
sum=sum+d;
}
}
printf("\n the value of total sum of the loop %d",sum);
}
int main(){
even_numbers_sum(100);
return 0;
}
1.first change is here in function declaration and definition you have to write int i in the parentheses.
void even_numbers_sum(int i)
2.Secondly there is no need to put the condition if you want to start from 0. it can be done by simply increment d by 2.
for(d=0;d<=i;d+=2)
3.Your main method has return type int so there should be some integer returned.
return 0;
I hope this will help you to solve your problem. If there is anything which you want to ask I'll be glad to help you.
Firstly, you should initialize sum as 0 at begin. sum may be not 0 without initialization.
Secondly, in your code, sum will be only add with the final even number (100), not add each each even number from 0 to 100.
A correct example as below:
#include <stdio.h>
int even_numbers_sum()
{
int d, sum = 0; // initialize sum as 0
for (d = 0; d <= 100; d++) {
if (d % 2 == 0) {
printf("\n this is even number loop %d", d);
sum = sum + d; // add each even number to sum
}
}
// sum=sum+d; // This line code will add final even number and sum
printf("\n the value of total sum of the loop %d", sum);
return sum;
}
int main()
{
even_numbers_sum();
}
I tried going beyond just guessing random numbers. The conditions were these:
use input() numbers used from 1 to100 and if inserted numbers that are out of this range, to show a line to re-enter a number
use output() to show the output(but show the last line```You got it right on your Nth try!" on the main())
make the inserted number keep showing on the next line.
Basically, the program should be made to show like this :
insert a number : 70
bigger than 0 smaller than 70.
insert a number : 35
bigger than 35 smaller than 70.
insert a number : 55
bigger than 55 smaller than 70.
insert a number : 60
bigger than 55 smaller than 60.
insert a number : 57
You got it right on your 5th try!
I've been working on this already for 6 hours now...(since I'm a beginner)... and thankfully I've been able to manage to get the basic structure so that the program would at least be able to show whether the number is bigger than the inserted number of smaller than the inserted number.
The problem is, I am unable to get the numbers to be keep showing on the line. For example, I can't the inserted number 70 keep showing on smaller than 70.
Also, I am unable to find out how to get the number of how many tries have been made. I first tried to put it in the input() as count = 0 ... count++; but failed in the output. Then I tried to put in in the output(), but the output wouldn't return the count so I failed again.
I hope to get advice on this problem.
The following is the code that I wrote that has no errors, but problems in that it doesn't match the conditions of the final outcome.
(By the way, I'm currently using Visual Studio 2017 which is why there is a line of #pragma warning (disable : 4996), and myflush instead of fflush.)
#include <stdlib.h>
#include <time.h>
#include <stdio.h>
#pragma warning (disable : 4996)
int input();
int random(int);
void myflush();
void output(int, int);
int main()
{
int num;
int i;
int ran;
srand((unsigned int)time(NULL));
i = 0;
while (i < 1) {
ran = 1 + random(101);
++i;
}
num = input();
output(ran, num);
printf("You got it right on your th try!");a
return 0;
}
int input()
{
int num;
printf("insert a number : ");
scanf("%d", &num);
while (num < 1 || num > 100 || getchar() != '\n') {
myflush();
printf("insert a number : ");
scanf("%d", &num);
}
return num;
}
int random(int n)
{
int res;
res = rand() % n;
return res;
}
void myflush()
{
while (getchar() != '\n') {
;
}
return;
}
void output(int ran, int num) {
while (1) {
if (num != ran){
if (num < ran) {
printf("bigger than %d \n", num); //
}
else if (num > ran) {
printf("smaller than %d.\n", num);
}
printf("insert a number : ");
scanf("%d", &num);
}
else {
break;
}
}
return;
}
There are many problem and possible simplifications in this code.
use fgets to read a line then scanf the line content. This avoids the need of myflush which doesn’t work properly.
the function random is not needed since picking a random number is a simple expression.
if the range of the random number is [1,100], you should use 1+rand()%100.
there is no real need for the function output since it’s the core of the main program. The input function is however good to keep to encapsulate input.
you should test the return value of scanf because the input may not always contain a number.
Here is a simplified code that provides the desired output.
#include <stdlib.h>
#include <time.h>
#include <stdio.h>
#pragma warning (disable : 4996)
int input() {
char line[100];
int num, nVal;
printf("insert a number : ");
fgets(line, sizeof line, stdin);
nVal = sscanf(line, "%d", &num);
while (nVal != 1 || num < 1 || num > 100) {
printf("insert a number : ");
fgets(line, sizeof line, stdin);
nVal = sscanf(line, "%d", &num);
}
return num;
}
int main()
{
int cnt = 0, lowerLimit = 0, upperLimit = 101;
srand((unsigned int)time(NULL));
// pick a random number in the range [1,100]
int ran = 1 + rand()%100;
while(1) {
cnt++;
int num = input();
if (num == ran)
break;
if (num > lowerLimit && num < upperLimit) {
if (num < ran)
lowerLimit = num;
else
upperLimit = num;
}
printf("bigger than %d and smaller than %d\n", lowerLimit, upperLimit);
}
printf("You got it right on your %dth try!\n", cnt);
return 0;
}
I am unable to find out how to get the number of how many tries have been made.
Change the output function from void to int so it can return a value for count, and note comments for other changes:
int output(int ran, int num) {//changed from void to int
int count = 0;//create a variable to track tries
while (1) {
if (num != ran){
count++;//increment tries here and...
if (num < ran) {
printf("bigger than %d \n", num); //
}
else if (num > ran) {
printf("smaller than %d.\n", num);
}
printf("insert a number : ");
scanf("%d", &num);
}
else {
count++;//... here
break;
}
}
return count;//return value for accumulated tries
}
Then in main:
//declare count
int count = 0;
...
count = output(ran, num);
printf("You got it right on your %dth try!", count);
With these modifications, your code ran as you described above.
(However, th doesn't work so well though for the 1st, 2nd or 3rd tries)
If you want the program to always display the highest entered number that is lower than the random number ("bigger than") and the lowest entered number that is higher then the random number ("smaller than"), then your program must remember these two numbers so it can update and print them as necessary.
In the function main, you could declare the following two ints:
int bigger_than, smaller_than;
These variables must go into the function main, because these numbers must be remembered for the entire duration of the program. The function main is the only function which runs for the entire program, all other functions only run for a short time. An alternative would be to declare these two variables as global. However, that is considered bad programming style.
These variables will of course have to be updated when the user enters a new number.
These two ints would have to be passed to the function output every time it is called, increasing the number of parameters of this function from 2 to 4.
If you want a counter to count the number of numbers entered, you will also have to remember this value in the function main (or as a global variable) and pass it to the function output. This will increase the number of parameters for the function to 5.
If you don't want to pass so many parameters to output, you could merge the contents of the functions output and input into the function main.
However, either way, you will have to move most of the "smaller than" and "bigger than" logic from the function output into the function main, because that logic is required for changing the new "bigger_than" and "smaller_than" int variables which belong to the function main. The function output should only contain the actual printing logic.
Although it is technically possible to change these two variables that belong to the function main from inside the function output, I don't recommend it, because that would get messy. It would require you to pass several pointers to the function output, which would allow that function to change the variables that belong to the function main.
I have now written my own solution and I found that it is much easier to write by merging the function output into main. I also merged all the other functions into main, but that wasn't as important as merging the function output.
Here is my code:
#include <stdlib.h>
#include <time.h>
#include <stdio.h>
#pragma warning (disable : 4996)
int main()
{
const char *ordinals[4] = { "st", "nd", "rd", "th" };
int num_tries = 0;
int bigger_than = 0, smaller_than = 101;
int input_num;
int random_num;
srand( (unsigned int)time( NULL ) );
random_num = 1 + rand() % 101;
for (;;) //infinite loop, equivalent to while(1)
{
printf( "Bigger than: %d, Smaller than: %d\n", bigger_than, smaller_than );
printf( "enter a number: " );
scanf( "%d", &input_num );
printf( "You entered: %d\n", input_num );
num_tries++;
if ( input_num == random_num ) break;
if ( input_num < random_num )
{
if ( bigger_than < input_num )
{
bigger_than = input_num;
}
}
else
{
if ( smaller_than > input_num )
{
smaller_than = input_num;
}
}
}
printf( "You got it right on your %d%s try!", num_tries, ordinals[num_tries<3?num_tries:3] );
return 0;
}
Also, I made sure that the program would print "1st", "2nd" and "3rd", whereas all the other solutions simply print "1th", "2th", "3th". I used the c++ conditional operator for this.
#include<stdio.h>
#include<conio.h>
#include<math.h>
void main()
{
int i , n , sum=0, rem;
clrscr();
for(i=1;i<=1000;i++)
{
while(i!=0)
{
rem = i%10;
sum = sum + pow(rem,3);
i = i / 10;
}
if(i == sum)
printf("\n %d", i);
}
getch();
}
I tried the above code for printing Armstrong Numbers upto 1000 . The output that I got was a list of zeros. I am not able to find the error in the code. Thanks in advance :)
You should keep a copy of i, so that it could be kept for comparison with the sum variable.
As of now, you compare sum and i, at every step when i has become 0.
You should use a temp variable to store value of i(before performing i/=10).
Also, you can't keep i in the while-loop as it would always be 0, and hence post increment will have no effect on it. You should need another temporary variable, say div.
And, you should finally print temp.
Also, an Armstrong number is an n-digit number that is equal to the sum of the nth powers of its digits.
So, for 1000, you need to caclculate the 4th power.
int temp,div;
for(i=1;i<=1000;i++)
{
temp = i;
div = i;
while(div!=0)
{
rem = div%10;
sum = sum + pow(rem,3);
div = div / 10;
}
if(temp == sum)
printf("\n %d", temp);
}
NOTE :- Probably you're using Turbo C compiler(check that header <conio.h>), which you shouldn't(you should avoid it). You should use GCC(on Linux system), CodeBlocks IDE(on Windows).
You can also use this code to print Armstrong number in given range.
#include<stdio.h>
int main()
{
int num,r,sum,temp;
int min,max;
printf("Enter the minimum range: ");
scanf("%d",&min);
printf("Enter the maximum range: ");
scanf("%d",&max);
printf("Armstrong numbers in given range are: ");
for(num=min;num<=max;num++)
{
temp=num;
sum = 0;
while(temp!=0)
{
r=temp%10;
temp=temp/10;
sum=sum+(r*r*r);
}
if(sum==num)
printf("%d ",num);
}
return 0;
}
Hey guys so I need to make a program which asks the user to enter a number as a argument and then let them know if it is a prime number or 0 otherwise. So the code I have so far is as follows but I am a little confused on how to make it run through all the possible values of the and make sure that it isn't a non-prime number. Right now what happens is that the program opens, I enter a value and nothing happens. Note: I have math in the header as I am unsure if it is needed or not at this stage.
EDIT: SO I MADE THE CHANGES SUGGESTED AND ALSO ADDED A FOR LOOP HOWEVER WHEN I GO TO COMPILE MY PROGRAM I GET AN WARNING SOMETHING ALONG THE LINES OF 'CONTROL MAY REACH END OF NON-VOID FUNCTION'. HOWEVER THE PROGRAM DOES COMPILE WHEN I GO TO ENTER A NUMBER AND HIT ENTER IRRELEVANT OT WHETHER OR NOT IT IS A PRIME NUMBER I GET AN ERROR BACK SAYING 'FLOATING POINT EXCEPTION: 8'.
EDIT 2: THE FLOATING POINT ERROR HAS BEEN FIXED HOWEVER NOW THE PROGRAM SEEMS TO THINK THAT EVERY NUMBER IS NON - PRIME AND OUTPUTS IT THIS WAY. I CAN'T SEEM TO SEE WHY IT WOULD DO THIS. I AM ALSO STILL GETTING THE 'CONTROL MAY REACH END OF NON-VOID FUNCTION' WARNING
#include <stdio.h>
#include <math.h>
int prime(int a){
int b;
for(b=1; b<=a; b++){
if (a%b==0)
return(0);
}
if(b==a){
return(1);
}
}
int main(void){
int c, answer;
printf("Please enter the number you would like to find is prime or not= ");
scanf("%d",&c);
answer = prime(c);
if(answer==1){
printf("%d is a prime number \n",c);
}
else
printf("%d is not a prime number\n",c);
}
1. You never initialized i (it has indeterminate value - local variable).
2. You never call function is_prime.
And using a loop will be good idea .Comparing to what you have right now.
I just modified your function a little. Here is the code
#include <stdio.h>
#include <math.h>
int prime(int a)
{
int b=2,n=0;
for(b=2; b<a; b++)
{
if (a%b==0)
{
n++;
break;
}
}
return(n);
}
int main(void)
{
int c, answer;
printf("Please enter the number you would like to find is prime or not= ");
scanf("%d",&c);
answer = prime(c);
if(answer==1)
{
printf("%d is not a prime number \n",c);
}
else
{
printf("%d is a prime number\n",c);
}
return 0;
}
Explanation-
In the for loop, I am starting from 2 because, I want to see if the given number is divisible by 2 or the number higher than 2. And I have used break, because once the number is divisible, I don't want to check anymore. So, it will exit the loop.
In your main function, you had not assigned properly for the printf() statement. If answer==1, it is not a prime number. (Because this implies that a number is divisible by some other number). You had written, it is a prime number(which was wrong).
If you have any doubts, let me hear them.
I suggest you start with trial division. What is the minimal set of numbers you need to divide by to decide whether a is prime? When can you prove that, if a has a factor q, it must have a smaller factor p? (Hint: it has a prime decomposition.)
Some errors your program had in your prime finding algorithm:
You start the loop with number 1 - this will make all numbers you test to be not prime, because when you test if the modulo of a division by 1 is zero, it's true (all numbers are divisible by 1).
You go through the loop until a, which modulo will also be zero (all number are divisible by themselves).
The condition for a number to be prime is that it must be divisible by 1 and itself. That's it. So you must not test that in that loop.
On main, the error you're getting (control reaches end of non-void function) is because you declare main to return an int.
int main(void)
And to solve that, you should put a return 0; statement on the end of your main function. Bellow, a working code.
#include <stdio.h>
#include <math.h>
int prime(int a)
{
int b;
for (b = 2; b < a; b++) {
if (a % b == 0)
return (0);
}
return 1;
}
int main(void)
{
int c, answer;
printf
("Please enter the number you would like to find is prime or not= ");
scanf("%d", &c);
answer = prime(c);
if (answer == 1) {
printf("%d is a prime number \n", c);
} else {
printf("%d is not a prime number\n", c);
}
return 0;
}
On a side note, don't use the CAPSLOCK to write full sentences. Seems like you're yelling.
Mathematically the maximum divisor of a number can be as a large as the square of it, so we just need to loop until sqrt(number).
A valid function would be:
//Function that returns 1 if number is prime and 0 if it's not
int prime(number) {
int i;
for (i = 2; i < sqrt(number); i++) {
if (a % i == 0)
return (0);
}
return 1;
}
#include<stdio.h>
int main()
{
int n , a, c = 0;
printf ("enter the value of number you want to check");
scanf ("%d", &n);
//Stopping user to enter 1 as an input.
if(n==1)
{
printf("%d cannot be entered as an input",n);
}
for(a = 2;a < n; a++)
{
if(n%a==0)
{
c=1;
break;
}
}
if(c==0 && n!=1)
{
printf("%d is a prime number \n",n);
}
else
{
if(c!=0 && n!=1)
{
printf("%d is not a prime number \n",n);
}
}
return 0;
}
#include <stdio.h>
#include <stdlib.h>
int main()
{
int x,i;
printf("enter the number : ");
scanf("%d",&x);
for ( i=2; i<x;i++){
if ( x % i == 0){
printf("%d",x);
printf(" is not prime number ");
printf("it can be divided by : ");
printf("%d",i);
break;
}[this is best solution ][1]
}
if( i>=x) {
printf("%d",x);
printf(" is prime number");
}
}
I am very new to C. I am using A modern Approach to C programming by King 2nd Edition.
I am stuck on chapter 6. Question 1: Write a program that finds the largest in a series of numbers entered by the user. The program must prompt the user to enter the numbers one by one. When the user enters 0 or a negative number, the program must display the largest non negative number entered.
So far I have:
#include <stdio.h>
int main(void)
{
float a, max, b;
for (a == max; a != 0; a++) {
printf("Enter number:");
scanf("%f", &a);
}
printf("Largest non negative number: %f", max);
return 0;
}
I do not understand the last part of the question, which is how to see which non-negative number is the greatest at the end of user input of the loop.
max = a > a ???
Thanks for your help!
So you want to update max if a is greater than it each iteration thru the loop, like so:
#include <stdio.h>
int main(void)
{
float max = 0, a;
do{
printf("Enter number:");
/* the space in front of the %f causes scanf to skip
* any whitespace. We check the return value to see
* whether something was *actually* read before we
* continue.
*/
if(scanf(" %f", &a) == 1) {
if(a > max){
max = a;
}
}
/* We could have combined the two if's above like this */
/* if((scanf(" %f", &a) == 1) && (a > max)) {
* max = a;
* }
*/
}
while(a > 0);
printf("Largest non negative number: %f", max);
return 0;
}
Then you simply print max at the end.
A do while loop is a better choice here because it needs to run at least once.
#include<stdio.h>
int main()
{
float enter_num,proc=0;
for(;;)
{
printf("Enter the number:");
scanf("%f",&enter_num);
if(enter_num == 0)
{
break;
}
if(enter_num < 0)
{
proc>enter_num;
proc=enter_num;
}
if(proc < enter_num)
{
proc = enter_num;
}
}
printf("Largest number from the above is:%.1f",proc);
return 0;
}