Programming Forums > Application Development > C++

jack999 · Apr 5th, 2006, 7:53 AM

hi guys

i'm a beginner in c++ and i have H.W to submit but i need some help

this is the question

Write a C-Program that reads five grades (Homework, Quizzes, Major1, Major2,
Final) for a number of students n (determined by the user).
o For each student
1- Calculates the total grade x: (Sum of the five grades)
2- Assign a letter grade (A+,A, B+, B, C+, C, D+, D, F) according to
the following rules :
Total Grade Letter Grade
95<= x <100 A+
90<= x < 94 A
85<= x < 89 B+
80<= x < 84 B
75<= x < 79 C+
70<= x <74 C
65<= x <69 D+
60<= x < 64 D
x<60 F
Print the total grade x and the letter grades
3- Calculate and print the number of students with each letter grade, the
format of the output must be like :
Letter Grade Number of students
------------------ --------------------------
A+ --
A -
B+ -
.
.
4- Calculate and print the max Total grade and the minimum Total grade

i solved #1 but there is a problem
i can solve 2,4 but 3 i need someone to explain it

(Toggle Plain Text)

#include<stdio.h>
#include<math.h>
main()
{
int n,i  ;
double x,hw,q,m1,m2,f,sum  ;
sum=0   ;
printf("enter number of students:");
scanf("%d",&n);
printf("enter the grade of hw,q,m1,m2 and f:");
scanf("%lf %lf %lf %lf %lf",&hw,&q,&m1,&m2,&f);

for(i=1,i<=n,i++)
{
scanf("%lf",&x);
sum+=x ;
}
x= hw+q+m1+m2+f      ;
scanf("%lf",&x);
printf("x=%lf",x);
}

jayme · Apr 5th, 2006, 8:02 AM

couldn't you just do something like

(Toggle Plain Text)

for(int i = 0; i < maxstudents; i++) std::cout << x << n << std::endl;

Cleaner of course. Use your imagination to make a table or something.

Seif · Apr 5th, 2006, 8:10 AM

Make your Code more readable by structuring it properly, and put it in code tags, and your much more likely to get some help, also this maybe best suited for the C section rather than C++.

I can't help you with your code as I'm not too hot on printf or scanf as its more for C... that and also the format of your code is making my eyes bleed.

nnxion · Apr 5th, 2006, 8:30 AM

Hi. Your post should be in the C forum
Making your code look like this makes it much easier to read:

(Toggle Plain Text)

#include <stdio.h>
#include <math.h>
main()
{
	int n, i;
	double x, hw, q, m1, m2, f, sum;
	sum = 0;

	printf("Enter number of students: ");
	scanf("%d", &n);

	printf("Enter the grade of Homework, Quizzes, Major1, Major2 and Final: ");
	scanf("%lf %lf %lf %lf %lf", &hw, &q, &m1, &m2, &f);

	for(i = 1; i <= n; i++)
	{
		scanf("%lf",&x);
		sum+=x ;
	}
	x = hw + q + m1 + m2 + f;
	scanf("%lf",&x);
	printf("x = %lf\n",x);
}

Please read the "How to post a question" thread at the top of the C or C++ forum. And restructure your question so it looks readable.

nnxion · Apr 5th, 2006, 9:24 AM

If you want to impress your teacher (or maybe not...), you can do this for your first part:

(Toggle Plain Text)

#include <stdio.h>
#include <math.h>

int main()
{
	int number = 0, current;
	double sum;

	char *gradenames[] =
	{
		"Homework", "Quizzes", "Major1", "Major2", "Final"
	};

	double grades[] =
	{
		0, 0, 0, 0, 0
	};

	printf("Enter number of students: ");
	if(scanf("%d", &number) != 1)
	{
		printf("IDIOT!\n");
		return 1;
	}

	for(current = 0; current < number; current++)
	{
		int t;
		sum = 0;
		printf("\nStudent #%d\n", current+1);
		for(t = 0; t < 5; t++)
		{
			printf("Enter the grade of %s: ", gradenames[t]);
			if(scanf("%lf", &grades[t]) != 1)
			{
				printf("IDIOT!\n");
				return 1;
			}
			sum += grades[t];
		}
		printf("Sum of student #%d is %.2lf\n\n", current+1, sum);
	}

	return 0;
}

Pizentios · Apr 5th, 2006, 9:37 AM

fixed code tags

Xyhm · Apr 5th, 2006, 9:37 AM

Wouldn't flushing (fflush(stdout)) after the printf's that doesn't use '\n' be a good idea?

nnxion · Apr 5th, 2006, 9:44 AM

Quote:

Originally Posted by Xyhm

Wouldn't flushing (fflush(stdout)) after the printf's that doesn't use '\n' be a good idea?

If it wrote to a file, I'd do that yes, but not normally. Btw '\n' doesn't flush the buffer, std::endl does. Flushing the stdin might be a good idea, but I'm not sure. DaWei or someoe else know?

Xyhm · Apr 5th, 2006, 10:34 AM

Quote:

Originally Posted by nnxion

If it wrote to a file, I'd do that yes, but not normally. Btw '\n' doesn't flush the buffer, std::endl does. Flushing the stdin might be a good idea, but I'm not sure. DaWei or someoe else know?

I've had problems with printf writing to the screen and not flushing afterwards. As for '\n', I've read somewhere that it makes flushing in these cases unnecessary, but I don't know why and it may very well not be true.

nnxion · Apr 5th, 2006, 10:56 AM

Quote:

Originally Posted by Xyhm

I've had problems with printf writing to the screen and not flushing afterwards. As for '\n', I've read somewhere that it makes flushing in these cases unnecessary, but I don't know why and it may very well not be true.

Like I said, it's true for std::endl, not for a newline character ('\n'). Strange that you had problems with that. Must have been something else. Or like DaWei said, mixing printf with cout.

@David: Thanx for clearing that up for me.

Apr 5th, 2006, 8:30 AM	#4
nnxion Programming Guru Join Date: Jun 2005 Location: elemental plane Posts: 1,429 Rep Power: 5	Hi. Your post should be in the C forum Making your code look like this makes it much easier to read: (Toggle Plain Text) #include <stdio.h> #include <math.h> main() { int n, i; double x, hw, q, m1, m2, f, sum; sum = 0; printf("Enter number of students: "); scanf("%d", &n); printf("Enter the grade of Homework, Quizzes, Major1, Major2 and Final: "); scanf("%lf %lf %lf %lf %lf", &hw, &q, &m1, &m2, &f); for(i = 1; i <= n; i++) { scanf("%lf",&x); sum+=x ; } x = hw + q + m1 + m2 + f; scanf("%lf",&x); printf("x = %lf\n",x); } #include <stdio.h> #include <math.h> main() { int n, i; double x, hw, q, m1, m2, f, sum; sum = 0; printf("Enter number of students: "); scanf("%d", &n); printf("Enter the grade of Homework, Quizzes, Major1, Major2 and Final: "); scanf("%lf %lf %lf %lf %lf", &hw, &q, &m1, &m2, &f); for(i = 1; i <= n; i++) { scanf("%lf",&x); sum+=x ; } x = hw + q + m1 + m2 + f; scanf("%lf",&x); printf("x = %lf\n",x); } Please read the "How to post a question" thread at the top of the C or C++ forum. And restructure your question so it looks readable. __________________ "Employ your time in improving yourself by other men's writings, so that you shall gain easily what others have labored hard for." -- Socrates

Apr 5th, 2006, 9:24 AM	#5
nnxion Programming Guru Join Date: Jun 2005 Location: elemental plane Posts: 1,429 Rep Power: 5	If you want to impress your teacher (or maybe not...), you can do this for your first part: (Toggle Plain Text) #include <stdio.h> #include <math.h> int main() { int number = 0, current; double sum; char gradenames[] = { "Homework", "Quizzes", "Major1", "Major2", "Final" }; double grades[] = { 0, 0, 0, 0, 0 }; printf("Enter number of students: "); if(scanf("%d", &number) != 1) { printf("IDIOT!\n"); return 1; } for(current = 0; current < number; current++) { int t; sum = 0; printf("\nStudent #%d\n", current+1); for(t = 0; t < 5; t++) { printf("Enter the grade of %s: ", gradenames[t]); if(scanf("%lf", &grades[t]) != 1) { printf("IDIOT!\n"); return 1; } sum += grades[t]; } printf("Sum of student #%d is %.2lf\n\n", current+1, sum); } return 0; } #include <stdio.h> #include <math.h> int main() { int number = 0, current; double sum; char gradenames[] = { "Homework", "Quizzes", "Major1", "Major2", "Final" }; double grades[] = { 0, 0, 0, 0, 0 }; printf("Enter number of students: "); if(scanf("%d", &number) != 1) { printf("IDIOT!\n"); return 1; } for(current = 0; current < number; current++) { int t; sum = 0; printf("\nStudent #%d\n", current+1); for(t = 0; t < 5; t++) { printf("Enter the grade of %s: ", gradenames[t]); if(scanf("%lf", &grades[t]) != 1) { printf("IDIOT!\n"); return 1; } sum += grades[t]; } printf("Sum of student #%d is %.2lf\n\n", current+1, sum); } return 0; } __________________ "Employ your time in improving yourself by other men's writings, so that you shall gain easily what others have labored hard for." -- Socrates

Apr 5th, 2006, 9:37 AM	#6
Pizentios Programming Guru Join Date: May 2004 Location: Brandon, Manitoba, Canada Posts: 2,023 Rep Power: 7	fixed code tags __________________ Profanity is the one language that all programmers understand. Check out my Blog <---updated Nov 30 2007!

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Apr 5th, 2006, 7:53 AM	#1
jack999 Newbie Join Date: Apr 2006 Posts: 5 Rep Power: 0	Help hi guys i'm a beginner in c++ and i have H.W to submit but i need some help this is the question Write a C-Program that reads five grades (Homework, Quizzes, Major1, Major2, Final) for a number of students n (determined by the user). o For each student 1- Calculates the total grade x: (Sum of the five grades) 2- Assign a letter grade (A+,A, B+, B, C+, C, D+, D, F) according to the following rules : Total Grade Letter Grade 95<= x <100 A+ 90<= x < 94 A 85<= x < 89 B+ 80<= x < 84 B 75<= x < 79 C+ 70<= x <74 C 65<= x <69 D+ 60<= x < 64 D x<60 F Print the total grade x and the letter grades 3- Calculate and print the number of students with each letter grade, the format of the output must be like : Letter Grade Number of students ------------------ -------------------------- A+ -- A - B+ - . . 4- Calculate and print the max Total grade and the minimum Total grade i solved #1 but there is a problem i can solve 2,4 but 3 i need someone to explain it (Toggle Plain Text) #include<stdio.h> #include<math.h> main() { int n,i ; double x,hw,q,m1,m2,f,sum ; sum=0 ; printf("enter number of students:"); scanf("%d",&n); printf("enter the grade of hw,q,m1,m2 and f:"); scanf("%lf %lf %lf %lf %lf",&hw,&q,&m1,&m2,&f); for(i=1,i<=n,i++) { scanf("%lf",&x); sum+=x ; } x= hw+q+m1+m2+f ; scanf("%lf",&x); printf("x=%lf",x); } #include<stdio.h> #include<math.h> main() { int n,i ; double x,hw,q,m1,m2,f,sum ; sum=0 ; printf("enter number of students:"); scanf("%d",&n); printf("enter the grade of hw,q,m1,m2 and f:"); scanf("%lf %lf %lf %lf %lf",&hw,&q,&m1,&m2,&f); for(i=1,i<=n,i++) { scanf("%lf",&x); sum+=x ; } x= hw+q+m1+m2+f ; scanf("%lf",&x); printf("x=%lf",x); } Last edited by Pizentios; Apr 5th, 2006 at 9:36 AM.

Apr 5th, 2006, 8:10 AM	#3
Seif Hobbyist Programmer Join Date: Jan 2006 Location: UK Posts: 242 Rep Power: 3	Make your Code more readable by structuring it properly, and put it in code tags, and your much more likely to get some help, also this maybe best suited for the C section rather than C++. I can't help you with your code as I'm not too hot on printf or scanf as its more for C... that and also the format of your code is making my eyes bleed.

Apr 5th, 2006, 9:37 AM	#7
Xyhm Programmer Join Date: Mar 2006 Posts: 60 Rep Power: 3	Wouldn't flushing (fflush(stdout)) after the printf's that doesn't use '\n' be a good idea?

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