#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#include <conio.h>
#include <math.h>

void Q1();
void Q2();
int Prime(int);

struct City
{
	int code;
	char name[100];
	int population;
};

typedef struct City city;

int main()
{


    char option;
    do
    {
        printf("\n\n\n");
        printf("\t**************************************************\n");
        printf("\t* Selecting appropriate action:                  *\n");
        printf("\t* 1. Question 1                                  *\n");
        printf("\t* 2. Question 2                                  *\n");
        printf("\t* 3. Quit program                                *\n");
        printf("\t**************************************************\n");
        _flushall();
        printf("\n\tYOUR OPTION IS : ");
        option=getche();
        switch(option)
        {
            case '1':
                Q1(); getch() ;
                system("cls") ;
                break ;
            case '2':
                Q2(); getch() ;
                system("cls") ;
                break ;
            case '3':
                return 0;
            default :
                getch() ;
                system("cls") ;
                printf("\n\n\n\tPlease type the number (1,2,3) again ");
        }
    }while(1);

}

void Q1()
{
	printf("\n\tQuestion 1 \n");
	printf("\n\tWrite a program to check whether a number is the prime or not ?\n");
	long n;
	printf("\n\tChecking the prime:\n");
	do
    {
        printf("\tEnter a number : ");
        scanf("%d",&n);
        if (n<1)
		{
			system("cls");
			printf("\n\tQuestion 1 \n");
			printf("\n\tPlease enter the number from 1\n");
		}while (n<1)

	}

	if (Prime(n)==0 || n==1)
	{
		printf("\tThis is not a prime\n");
	}
	else
	{
		printf("\tThis is a prime\n");
	}

}

int Prime(int n)
{
	int i;
	for(i=2;i<=sqrt(n);i++)
	{
		if(n%i==0)
			return 0;
	}
	return 1;
}


void Q2()
{
	printf("\n\tQuestion 2 \n");
	int i,n,max ;
	do
	{
		printf("\n\n\tEnter a number of cities (1-10) : ");
		scanf("%d",&n);
		if (n<0 || n>10)
		{
			system("cls");
			printf("\n\tQuestion 2 \n");
			printf("\n\tPlease enter the number from 1 to 10\n");
		}


	}while (n<0||n>10);

	city list[n];
	max=0;
	for(i=0;i<n;i++)
	{
		printf("\n\tInput for city %d",i+1);
		printf("\n\t\tPlease enter the Area Code : ");
		scanf("%d",&list[i].code);
		_flushall();
		printf("\t\tPlease enter the Name : ");
		gets(list[i].name);
		printf("\t\tPlease enter the Population : ");
		scanf("%d",&list[i].population);
		max=(list[max].population>list[i].population)?max:i;
	}

	for(i=0;i<n;i++)
	{
		printf("\n\n\tCity %d : ",i+1);
		printf("\n\t\tCode : %d",list[i].code);
		printf("\n\t\tName : %s",list[i].name);
		printf("\n\t\tPopulation : %d",list[i].population);
	}

		printf("\n\n\tCity's most population : ");
		printf("\n\t\tCode : %d",list[max].code);
		printf("\n\t\tName : %s",list[max].name);
		printf("\n\t\tPopulation : %d",list[max].population);
}