//6) Write a function ``replace'' which takes a string as a parameter and replaces all spaces in that
                //string by minus signs and delivers the number of spaces it replaced
                #include <stdio.h>
                #include <string.h>

                void replace(char s[],int size)
                {
                    int a=0;
                    for(int i=0; i<size ; i++)
                    {
                        if(s[i]==' ')
                        {
                            s[i]='-';
                            a++;
                        }
                    }
                    printf("the number of spaces it replaced: %d\n",a);
                    printf("string after modify: %s",s);
                }

                int main()
                {
                    char s[20];
                    printf("enter the string : ");
                    gets(s);
                    replace(s,20);
                }

                //--------------------------------------------------------------------------------------------------

                //7) What is the output of these codes?
                a)	Output => 0 2 1
                b)	Output => -1, 0, 6, 7, 8, 9

                //--------------------------------------------------------------------------------------------------

                //8) Declare a structure Employee with id_no, salary, birth_date – which is day, month, and year- id
                //for 5 tasks the employee has. For example the data for an employee may be: id_no = 5, salary =
                //7500, birth_date = { day= 3, month= 8, year = 1980}, tasks_ids = {1, 3, 4, 9, 12}.
                #include <stdio.h>
                #include <string.h>
                const int size;
                struct date
                {
                        int day,month,year;
                };
                struct employement
                {
                        int id_no; int salary; int tasks[5];
                        struct date birth;
                };

                void inputemployee();
                void search_returnSalary();

                int main()
                {
                    struct employement employees[size];
                    printf("enter number of employees: ");
                    scanf("%d",&size);
                    search_returnSalary(employees,size);
                }

                void inputemployee(struct employement e[],int size_e)
                {
                    for(int i=0 ;i<size_e;i++)
                    {   printf("enter id_no for employee#%d: ",i+1);
                        scanf("%d",&e[i].id_no);
                        printf("enter salary for employee#%d: ",i+1);
                        scanf("%d",&e[i].salary);
                        printf("enter birthday(dd mm yy) for employee#%d: ",i+1);
                        scanf("%d%d%d",&e[i].birth.day,&e[i].birth.month,&e[i].birth.year);
                        for(int j=0; j<5 ; j++)
                        {
                            printf("enter task#%d: ",j+1);
                            scanf("%d",&e[i].tasks[j]);
                        }
                        printf("______________________________\n");
                    }
                }

                void search_returnSalary(struct employement e[],int size_e)
                {
                    inputemployee(e,size);
                    int id;
                    printf("enter the id_no to search it: ");
                    scanf("%d",&id);
                    for(int i=0 ;i<size_e;i++)
                    {
                        if(id==e[i].id_no)
                            printf("the salary of emloyee's(%d): %d",id,e[i].salary);
                    }
                }

                //--------------------------------------------------------------------------------------------------

                //9) Show the output:
                Output => The size of a_struct: 16-byte