I just started learning C and I'm trying to create a simple "Guess the Number" game.
Player 1 will enter a number that is between 1 and 1000.
Player 2 will be given 10 chances to guess the number entered by Player 1.
If Player 2's guess is beyond the range (1 to 1000), the system should display "Invalid. Out of range." instead of "Too high" or "Too low".
Currently, my program does not validate whether Player 2's guess is within the range (1 to 1000). Instead, it will just display "Too high" even if Player 2's guess is 2000 which is beyond the range (1 to 1000)
Here is my code:
#include <stdio.h>
int main()
{
int number, guess, count = 10;
printf("Enter a number between 1 and 1000:\n");
scanf("%d",&number);
while(number < 1 || number > 1000)
{
printf("Number is out of range.\n");
printf("Enter a number between 1 and 1000:\n");
scanf("%d",&number);
}
while(count >= 1 && count <= 10)
{
printf("Player 2, you have %d guesses remaining.\n", count);
printf("Enter your guess:\n");
scanf("%d", &guess);
count = count - 1;
if (guess >= 1 || guess <= 1000)
{
if (guess > number)
{
printf("Too high.\n");
}
else if (guess < number)
{
printf("Too low.\n");
}
else if (guess == number)
{
printf("Player 2 wins.\n");
}
}
else
{
printf("Invalid. Out of range.");
}
}
if (count == 0)
{
printf("Player 1 wins.");
}
return 0;
}
You need to change
if (guess >= 1 || guess <= 1000)
to
if (guess >= 1 && guess <= 1000)
to avoid values outside 1 and 1000. Otherwise, an input of 2000, will match the condition guess >= 1 and as per the short circuit property, it'll evaluate the if condition as truthy and control will never go to else block.
guess >= 1 || guess <= 1000 should be guess >= 1 && guess <= 1000
I am still learning to code and wrote this code to get the total after the weight and distance are calculated. Can someone tell my why the math is not working?
Example: When I enter 5 for weight and 1500 miles instead of getting 8.20 back I get 3.50.
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main(){
double weight,mileCost;
int miles, segment, remainder, stop = 1;
while(stop == 1){
printf("Charge by weight:(We don't tale packages over 10lbs\n");
printf("\n 1-2 lbs: $1.50\n 3-6 lbs: $3.70\n 7-10 lbs: $5.25\n ");
printf("Enter your package's weight:\n");
scanf("%f", &weight);
printf("Charge by mile: \n");
printf("$1.50 for every 500 miles\n");
printf("Enter the total miles for your package:\n");
scanf("%d", &miles);
if(miles == 0 || weight == 0 || weight > 10){
printf("Invalid entry! Try Again.");
}
segment= ceil((double) miles / 500);
remainder = miles % 500;
if(remainder > 0)
remainder = 1;
if(weight <= 2){
mileCost = 1.50 * (segment + remainder);
printf("The shipping charge for your package is: %f\n", mileCost);
}
else if(weight > 2 && weight <= 6){
mileCost = 3.70 * (segment + remainder);
printf("The shipping charge for your package is: %f\n", mileCost);
}
if(weight > 6 && weight <= 10){
mileCost = 5.25 * (segment + remainder);
printf("The shipping charge for your package is: %f\n", mileCost);
}
system("pause");
printf("Would you like to ship another package?\n Enter 1 to continue or 0 to stop. \n");
scanf("%d", &stop);
if(stop == 0){
printf("Thank you for your business! \n");
}
}
return 0;
}
Changing double weight, mileCost; to float weight, mileCost; will make it work since you are reading the variable from stdin using scanf("%f", &weight) (for floats) and not scanf("%lf", &weight) (for double).
I am still puzzled by why you do this:
if(remainder > 0)
remainder = 1;
Wouldn't ceil() already handle that in:
segment = ceil((double) miles / 500);
Also, based on the formula you provided, inputting weight=5 and miles=1500 should output 11.1.
You must use "lf" for a reading of a double variable:
scanf("%lf", &weight);
I am a new C programming learner, I am trying to make a program which would calculate the GPA of a student on the basis of grade marks input and credits of a subject.
The problem I am having is I want to limit the number of subjects input from 2 to 6 only.
Another problem is I want to limit the user to input integer from 1 to 100 only, instead of any other keywords, special characters (EOF)
I have put the "###" in comment line where I require these modifications.
#include <stdio.h>
int main(void) {
// input user input -- hopefully a number
// temp used to collect garbage characters
// status did the user enter a number?
// counter for keeping track of loop repetition
// no no. of subjects to be entered by user.
// credits credits per subject
// grades grades acheived in each subject (1 to 100).
// grade_value for holding the value of each subject grade (for ex; 80 to hundred is 4.0)
// grade_points Grade points for each subject (credits * grade_value)
// sum sum of total grade points
int counter = 1, subjects, no, credits, grades, status, temp;
float grade_value, grade_point, sum;
printf("Enter number of subjects you took for current semester: ");
status = scanf("%d", & no);
// ### I want to limit this integer input to be >=2 && <=6.
while (status != 1) {
while ((temp = getchar()) != EOF && temp != '\n');
if ((temp < 2) && (temp > 6));
break;
printf("Invalid input... please enter the number of subject again: ");
status = scanf("%d", & no);
}
// ### I want to be this input to block other character inputs than integer from 1 to hundred.
while (counter <= no) {
printf("\nEnter Subject %d grades separated with credits \n", counter);
scanf("%d %d", & grades, & credits);
if ((grades > 0) && (grades <= 29)) {
grade_value = 0;
printf("Grade value for subject %d is: %.2f", counter, grade_value);
grade_point = credits * grade_value;
printf("\nGrade point for subject %d is: %.2f", counter, grade_point);
sum = sum + grade_point;
++counter;
} else if ((grades >= 30) && (grades <= 34)) {
grade_value = 0.67;
printf("Grade value for subject %d is: %.2f", counter, grade_value);
grade_point = credits * grade_value;
printf("\nGrade point for subject %d is: %.2f", counter, grade_point);
sum = sum + grade_point;
++counter;
} else if ((grades >= 35) && (grades <= 39)) {
grade_value = 1;
printf("Grade value for subject %d is: %.2f", counter, grade_value);
grade_point = credits * grade_value;
printf("\nGrade point for subject %d is: %.2f", counter, grade_point);
sum = sum + grade_point;
++counter;
} else if ((grades >= 40) && (grades <= 44)) {
grade_value = 1.33;
printf("Grade value for subject %d is: %.2f", counter, grade_value);
grade_point = credits * grade_value;
printf("\nGrade point for subject %d is: %.2f", counter, grade_point);
sum = sum + grade_point;
++counter;
} else if ((grades >= 45) && (grades <= 49)) {
grade_value = 1.67;
printf("Grade value for subject %d is: %.2f", counter, grade_value);
grade_point = credits * grade_value;
printf(" \nGrade point for subject %d is: %.2f", counter, grade_point);
sum = sum + grade_point;
++counter;
} else if ((grades >= 50) && (grades <= 54)) {
grade_value = 2;
printf("Grade value for subject %d is: %.2f", counter, grade_value);
grade_point = credits * grade_value;
printf("\nGrade point for subject %d is: %.2f", counter, grade_point);
sum = sum + grade_point;
++counter;
} else if ((grades >= 55) && (grades <= 59)) {
grade_value = 2.33;
printf("Grade value for subject %d is: %.2f", counter, grade_value);
grade_point = credits * grade_value;
printf("\nGrade point for subject %d is: %.2f", counter, grade_point);
sum = sum + grade_point;
++counter;
} else if ((grades >= 60) && (grades <= 64)) {
grade_value = 2.67;
printf("Grade value for subject %d is: %.2f", counter, grade_value);
grade_point = credits * grade_value;
printf("\nGrade point for subject %d is: %.2f", counter, grade_point);
sum = sum + grade_point;
++counter;
} else if ((grades >= 65) && (grades <= 69)) {
grade_value = 3;
printf("Grade value for subject %d is: %.2f", counter, grade_value);
grade_point = credits * grade_value;
printf("\nGrade point for subject %d is: %.2f", counter, grade_point);
sum = sum + grade_point;
++counter;
} else if ((grades >= 70) && (grades <= 74)) {
grade_value = 3.33;
printf("Grade value for subject %d is: %.2f", counter, grade_value);
grade_point = credits * grade_value;
printf("\nGrade point for subject %d is: %.2f", counter, grade_point);
sum = sum + grade_point;
++counter;
} else if ((grades >= 75) && (grades <= 79)) {
grade_value = 3.67;
printf("Grade value for subject %d is: %.2f", counter, grade_value);
grade_point = credits * grade_value;
printf("\nGrade point for subject %d is: %.2f", counter, grade_point);
sum = sum + grade_point;
++counter;
} else if ((grades >= 80) && (grades <= 100)) {
grade_value = 4;
printf("Grade value for subject %d is: %.2f", counter, grade_value);
grade_point = credits * grade_value;
printf("\nGrade point for subject %d is: %.2f", counter, grade_point);
sum = sum + grade_point;
++counter;
}
// To print a message if user doesnt enter an integer varying from 1 to 100.
else {
printf("\n Error Grade input, Please Key in Again. (1 to 100 only.)");
}
}
printf("\n");
printf("\n");
printf("\nThe GPA is: %.2f", sum);
if (sum <= 49) {
printf("\nYou can register for 2 subjects for next semester.");
} else if ((sum >= 50) && (sum >= 79)) {
printf("\nYou can register for 5 subjects for next semester.");
} else if ((sum >= 80) && (sum <= 100)) {
printf("\nYou can register for 6 subjects for next semester.");
}
printf("\n");
printf("\n");
printf("\n_______________________________________________________");
printf("\nEnd of program");
return 0;
}
A do-while loop is perfect for loops that need to be called at least once and will get rid of your duplicated code. Reading unstructured input, possibly from the keyboard, (one could call, ./a.out < text.txt,) is actually something that is tricky to get right.
Luckily, the C FAQ has lots of advice, eg, http://c-faq.com/stdio/scanfprobs.html. It's going to be very arduous without functions, though. From limited testing, I'm pretty sure that this is a solid way to read the first variable.
#include <stdio.h> /* fgets sscanf */
#include <stdlib.h> /* EXIT_ printf fprintf */
#include <string.h> /* strlen */
int main(void) {
int no;
/* Input number, no \in [2, 6], and make sure that the read cursor is on
the next line. */
do {
char buffer[80];
size_t len;
printf("Enter number of subjects you took for current semester, [2, 6]: ");
/* On the advice of http://c-faq.com/stdio/scanfprobs.html, this reads
into a buffer first. */
if(!fgets(buffer, sizeof buffer, stdin)) {
if(feof(stdin)) {
fprintf(stderr, "Premature EOF.\n");
} else {
/* On IEEE Std 1003.1-2001-conforming systems, this will print
a meaningful error. */
perror("stdin");
}
/* Can't really do anything interactive once stdin has a read
error. */
return EXIT_FAILURE;
}
/* This is always going to be true, but segfaults if not. Paranoid. */
if(!(len = strlen(buffer))) continue;
/* Normally fgets stores a '\n' at the end; check. */
if(buffer[len - 1] != '\n') {
/* Check if the length of the buffer is big enough to hold input. */
if(len >= sizeof buffer - 1) {
int c;
fprintf(stderr, "Line too long.\n");
/* Flush whole line. http://c-faq.com/stdio/stdinflush2.html */
while((c = getchar()) != '\n') {
if(c != EOF) continue;
if(feof(stdin)) fprintf(stderr, "Premature EOF.\n");
else perror("stdin");
return EXIT_FAILURE;
}
continue;
} else {
/* Non-POSIX lines, eg, file without '\n' terminating. */
fprintf(stderr, "Note: line without line break detected.\n");
}
}
/* Parse buffer for a number that's between [2, 6]. Ignore the rest. */
if(sscanf(buffer, "%d", &no) != 1 || no < 2 || no > 6) {
fprintf(stderr, "Invalid input.\n");
continue;
}
/* Now no \in [2, 6]. */
printf("no: %d\n", no);
break;
} while(1);
return EXIT_SUCCESS;
}
One may be able to get away with a subset of this if your teacher enters only well-formed numbers.
Your code has some semantic mistakes. You must never put a semicolon after a if statement. Also you can write a more legible code by spacing blocks of code. Even better, you could refactor some blocks and encapsulate it into functions. Aside of that, see this solutions:
For the first problem, it can be solved with few lines of code. It's a good practice that the user know the restrictions of inputs before enter his input:
/* ### I want to limit this integer input to be >=2 && <=6. */
#include <stdio.h>
int main()
{
int no;
do {
printf("Enter number of subjects you took for current semester (2~6): ");
scanf("%d", &no);
} while (no < 2 || no > 6);
return 0;
}
The other issue can be solved by using the Standard C Library. Just #include <string.h> and #include <ctype.h>
#include <stdio.h>
#include <string.h> /* strlen() */
#include <ctype.h> /* isdigit() */
int main()
{
int n, invalidInput, status;
char strInput[5];
int i; /* for loop */
do {
invalidInput = 0;
printf("Enter a **number** between 1 and 100: ");
fflush(stdin);
status = scanf("%4s", strInput); /* read at maximum 4 chars from stdin */
if (status > 3) {
continue; /* try again */
}
for (i = 0; i < strlen(strInput); ++i) { /* ensure that all characters are numbers */
if (!isdigit(strInput[i])) {
invalidInput = 1;
break;
}
}
if (!invalidInput) {
n = atoi(strInput); /* now your input is a integer */
if (n < 1 || n > 100) {
printf("Error: the input must be between 1 and 100.\n");
invalidInput = 1;
}
}
} while (invalidInput); /* repeat until all chars are digits and they are in the required interval */
return 0;
}
I've made a program that is a cheque generator. Whatever amount you input in the scanf will output in words. For example if I were to to input "1234.56" My output will be "One Thousand Two Hundred Thirty Four Dollars and ... 56 Cents", or if I wanted to input the amount "0.01" the output will be "Zero Dollars and ... 1 Cents". The program works perfectly, however there is a minor issue, if I wanted to input the amount "9909" it will output "Nine Thousand Nine Hundred Ninety Nine Dollars and ... 0 Cents". The output should be "Nine Thousand Nine Hundred Nine Dollars and ... 0 Cents". Please help!
The code is as follows:
#include <stdio.h>
void printNum(int);
void printNum2(int);
int main()
{
int a = 0;
int b = 0;
int c = 0;
int d = 0;
int num = 0;
int printcents; //To convert the float "cents" to an integer.
float inclusive;
float cents;
printf("Welcome to the IPC144 Cheque Generator!!\n");
printf("PAY TO THE ORDER OF... amahmood29 (018359133)\n");
printf("Enter a monetary value from $0.01 to $9999.99 inclusive: ");
scanf("%f", &inclusive);
if(inclusive < 0.00 || inclusive >= 10000.00) {
printf("Sorry, cannot create cheque for that amount, try again next time!\n");
}
else
{
a = inclusive / 1000; //This data is replacing our variable by diving whatever the vaulue is by either 1000, 100, 10.
inclusive = inclusive - (a*1000);
b = inclusive / 100;
inclusive = inclusive - (b*100);
if ( inclusive > 19 ){
c = inclusive / 10;
inclusive = inclusive - (c*10);
}
else
{
c = inclusive;
d = 0;
}
d = inclusive;
num = inclusive;
cents = (inclusive - num)*100; //To calculate our "Cents" with numerals.
printcents = cents;
/*Printing if the variables are in the thousands, hundreds, tens or ones categories.*/
if (c == 0 && b == 0 && a == 0){
printf("Zero Dollars and ... %d Cents\n", printcents);
}
else{
if (a > 0){
printNum(a);
printf("Thousand ");
}
if (b > 0){
printNum(b);
printf("Hundred ");
}
printNum2(c);
if (d >= 0){
printNum(d);
printf("Dollars and ... ");
}
printf("%d", printcents);
printf(" Cents\n");
}
}
}
void printNum(int x) //Created functions to easily output various if statements.
{
if ( x == 1)
printf("One ");
else if ( x == 2)
printf("Two ");
else if (x == 3)
printf("Three ");
else if (x == 4)
printf("Four ");
else if (x == 5)
printf("Five ");
else if (x == 6)
printf("Six ");
else if (x == 7)
printf("Seven ");
else if (x == 8)
printf("Eight ");
else if (x == 9)
printf("Nine ");
}
void printNum2(int x)
{
if ( x == 10)
printf("Ten ");
else if ( x == 11)
printf("Eleven ");
else if ( x == 12)
printf("Twelve ");
else if ( x == 13)
printf("Thirteen ");
else if (x == 14)
printf("Fourteen ");
else if (x == 15)
printf("Fifteen ");
else if (x == 16)
printf("Sixteen ");
else if (x == 17)
printf("Seventeen ");
else if (x == 18)
printf("Eighteen ");
else if (x == 19)
printf("Nineteen ");
else if (x == 2)
printf("Twenty ");
else if (x == 3)
printf("Thirty ");
else if (x == 4)
printf("Forty ");
else if (x == 5)
printf("Fifty ");
else if (x == 6)
printf("Sixty ");
else if (x == 7)
printf("Seventy ");
else if (x == 8)
printf("Eighty ");
else if (x == 9)
printf("Ninety ");
}
I have been coding for a month now so I apologize for the simple errors.
After you have calculated b and adjusted inclusive so it is now 9, you get to your else case, which sets c to 9 (hence the Ninety output) and d to 0, but immediately afterwards sets d to 9 (hence the Nine in the output). I think you mixed up c and d in the else case.
I have a friend who was working on a c example from a book and he did a code like
#include<stdio.h>
#include<math.h>
#pragma warning(disable:4996)
int main()
{
float numGrade;
printf("\n\nPlease enter your numerical grade: ");
scanf("%f", &numGrade);
if (numGrade >= 90)
printf("\nYou got an A.\n\n");
else if (90 > numGrade >= 80)
printf("\nYou got a B.\n\n");
else if (80 > numGrade >= 70)
printf("\nYou got a C.\n\n");
else if (70 > numGrade >= 60)
printf("\nYou got a D.\n\n");
else if (60 > numGrade)
printf("\nYou got an F.\n\n");
else
printf("\nThis is an invalid grade!\n");
}
Is there any problem with doing it like that or should he do it like :
int main()
{
float numGrade;
printf("\n\nPlease enter your numerical grade: ");
scanf("%f", &numGrade);
if (numGrade >= 90)
printf("\nYou got an A.\n\n");
else if (90 > numGrade && numGrade >= 80)
printf("\nYou got a B.\n\n");
else if (80 > numGrade && numGrade >= 70)
printf("\nYou got a C.\n\n");
else if (70 > numGrade && numGrade >= 60)
printf("\nYou got a D.\n\n");
else if (60 > numGrade)
printf("\nYou got an F.\n\n");
else
printf("\nThis is an invalid grade!\n");
}
That first example won't work at all.
The first comparison in each test will return either 0 or 1. So it will always fail the second.
EDIT:
However, the program will probably still "work" the way it is desired, simply because the second comparison in each test is not needed.