11.1

#include <iostream>
#include <cmath>
#include<stdlib.h>
using namespace std;
typedef struct Pipe {
double diameter ;//[mm]
double length;//[m]
double thickness ; //[mm]
char *material; // "cast iron" "steel" "Cu" "PVC" "Al"

} PIPE;//====================
void display_pipe(PIPE pipe0);
void create_pipe(PIPE *pipe0);
int main() //how to use structures!!!!---------------
{ PIPE pipe1 = {50.,  1.5, 5, "steel"};
PIPE pipe2,pipe3;
pipe2.diameter = 30.;//alternative way of declaring struct--------------------------
pipe2.thickness = 2.;
pipe2.length = 5.;
pipe2.material= "cast iron";
PIPE *p1= &pipe3;//pointer to structure PIPE//alternative way of declaring struct--------------------------
p1->diameter = 40.;
p1->length=6.;
p1->thickness = 3.;
p1->material="Cu";
display_pipe(pipe1);
display_pipe(pipe2);
display_pipe(pipe3);
create_pipe(&pipe1);
display_pipe(pipe1);
    return 0;
}//---------------------------------
void create_pipe(PIPE *pipe0){
    pipe0->length = (rand()%(61+10)/10.+1.);//range 1 to 7 metres[m]
    pipe0->diameter = rand()%61+10; //10-70[mm]
    pipe0->thickness = rand()%11+1;//1-10[mm]
    int a = rand()%5+1;//1-5
    if (a==1)pipe0->material="steel";
        if (a==2)pipe0->material="Cu";
    if (a==3)pipe0->material="cast iron";
    if (a==4)pipe0->material="PVC";
    if (a==5)pipe0->material="Al";
}
void display_pipe(PIPE pipe0){
    cout<<"Pipe parameters"<<endl;
    cout<<" diameter  "<<pipe0.diameter<<endl;
cout<<" length "<<pipe0.length<<endl;
cout<<" thickness  "<<pipe0.thickness<<endl;
cout<<" material  "<<pipe0.material<<endl<<endl;}