#include <glpk.h>
#include <stdio.h>
#include <stdlib.h>
# define MC 3.0

int main(){
	int n,m,N;  //n = nu. of students  , m = no. of courses , N = max course per student
	
	n = 5,m = 5, N = 3;
	int M[m] ; //array of max students per course

	int sc[n][m] ;
	for(int i = 0;i<n;i++){
		for(int j = 0; j<m;j++){ 
			sc[i][j] = rand()%2;  //initialising the course preference by either zero or one
		}
		M[i] = rand()%m + 1; //max students pre course from 2-9
	}
	
	glp_prob *lp;
	int ia[1+1000],ja[1+1000];
	double ar[1+1000],z;
	lp = glp_create_prob();
	glp_set_prob_name(lp,"problem 1");
	glp_set_obj_dir(lp,GLP_MAX);
	char buf[10];
	glp_add_rows(lp,m+m+m);
	int index = 1;
	for(int i = 0; i<m;i++){
		snprintf(buf, m, "xss%d", i);
		glp_set_row_name(lp,index,buf);
		glp_set_row_bnds(lp,index,GLP_UP,0.0,N);
		index+=1;
	}
	for(int i = 0; i<m;i++){
		snprintf(buf, m, "xcc%d", i);
		glp_set_row_name(lp,index,buf);
		glp_set_row_bnds(lp,index,GLP_UP,0.0,M[i]);
		index+=1;
	}
	for(int i = 0; i<m;i++){
		snprintf(buf, m, "xsc%d", i);
		glp_set_row_name(lp,index,buf);
		glp_set_row_bnds(lp,index,GLP_UP,0.0,1.0);
		index+=1;
	}


	glp_add_cols(lp,m);
	
   
	for(int i =1;i<=m;i++){
		for(int j=0;j<n;j++){

		snprintf(buf, m, "x%d", i);
		glp_set_col_name(lp,i,buf);
		glp_set_col_bnds(lp,i,GLP_LO,0.0,0.0);
		glp_set_obj_coef(lp,i,1.0);
		}
	}
	index=1;
	for(int i = 0 ; i<n ; i++){
		for(int j = 0 ; j<m ;j++){
			ia[index] = i+1;
			ja[index] = j+1;
			ar[index] = sc[i][j];
			index+=1;
		}
	}
	glp_load_matrix(lp,m*n,ia,ja,ar);
	glp_simplex(lp,NULL);
	z = glp_get_obj_val(lp);
	double x[m];
	for(int i=0;i<m;i++){
		x[i] = glp_get_col_prim(lp,i+1);
	}
	printf("Maximum total number of courses taken by all students: %g\n",z);
	for(int i =0;i<m;i++){
		printf("%g\t",x[i]);
	}
	printf("\n");
	glp_delete_prob(lp);
	return 0;

}

C Language online compiler

Write, Run & Share C Language code online using OneCompiler's C online compiler for free. It's one of the robust, feature-rich online compilers for C language, running the latest C version which is C18. Getting started with the OneCompiler's C editor is really simple and pretty fast. The editor shows sample boilerplate code when you choose language as 'C' and start coding!

Read inputs from stdin

OneCompiler's C online editor supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample C program which takes name as input and print your name with hello.

#include <stdio.h>
int main()
{
    char name[50];
    printf("Enter name:");
    scanf("%s", name);
    printf("Hello %s \n" , name );
    return 0;
    
}

About C

C language is one of the most popular general-purpose programming language developed by Dennis Ritchie at Bell laboratories for UNIX operating system. The initial release of C Language was in the year 1972. Most of the desktop operating systems are written in C Language.

Key features:

  • Structured Programming
  • Popular system programming language
  • UNIX, MySQL and Oracle are completely written in C.
  • Supports variety of platforms
  • Efficient and also handle low-level activities.
  • As fast as assembly language and hence used as system development language.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition if-else is used.

if(conditional-expression) {
   // code
} else {
   // code
}

You can also use if-else for nested Ifs and if-else-if ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to if-else-if ladder.

switch(conditional-expression) {    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
...    
    
default:     
 // code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  // code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while(condition) {  
 // code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {
  // code 
} while (condition);

Arrays

Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.

Syntax

One dimentional Array:

data-type array-name[size];

Two dimensional array:

data-type array-name[size][size];

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity.

Two types of functions are present in C

  1. Library Functions:

Library functions are the in-built functions which are declared in header files like printf(),scanf(),puts(),gets() etc.,

  1. User defined functions:

User defined functions are the ones which are written by the programmer based on the requirement.

How to declare a Function

return_type function_name(parameters);

How to call a Function

function_name (parameters)

How to define a Function

return_type function_name(parameters) {  
  //code
}