C + + Example exercises (2)

Environment: dev-c++ (version:5.6.1)

1. Loop through a 1-1000 integer to determine if it is a prime number (input 1 o'clock end of program)

Primes: divisible by only 1 and itself.

Implementation code:

#include <iostream>#include<cstdlib>#include<cassert>using namespacestd;/**function name:isprimenumber. *precondition:parameter value is more than zero and less than or equal one thousand. *p Ostcondition:return True when parameter value is prime number.*/BOOLIsprimenumber (Const int&Number );intMain () { while(true)    {        intNumber ; cout<<"Please input a integer number (0-1000):"<<Endl; CIN>>Number ; //conditionASSERT (number>0&&number<= +); if(Number = =1) {             Break; }                BOOLFlag; Flag=isprimenumber (number); if(flag) {cout<<"Yes, the number is prime number."<<Endl; } Else{cout<<"No, the number is not prime number."<<Endl; }    }    returnexit_success;}BOOLIsprimenumber (Const int&Number ) {     for(intI=2; i<number/2+1; i++) {        if(number%i = =0) {            return false; }     }    return true;} 

2. Use class to achieve input and output time (time: minutes: seconds)

Requirements: Change data members to private, implement input and output functions with member functions, define member functions in the class body

Code implementation:

(For the rationality of time input, it is simple to use assert assert function to deal with, unreasonable, the program ends the operation directly)

#include <iostream>#include<cstdlib>#include<cassert>using namespacestd;classtime{ Public:        voidSet_time (Time &Time ) {cout<<"Hour (0-23):"<<Endl; CIN>>Time.hour; ASSERT (Time.hour>0&&time.hour< -); cout<<"minute (0-59):"<<Endl; CIN>>Time.minute; ASSERT (Time.minute>0&&time.minute< -); cout<<"second (0-59):"<<Endl; CIN>>time.sec; ASSERT (Time.sec>0&&time.sec< -); }        voidShow_time (ConstTime &Time ) {cout<<time.hour<<":"<<time.minute<<":"<<time.sec<<Endl; }    Private:        inthour; intminute; intsec;};intMain () {time t;    T.set_time (t);    T.show_time (t); returnexit_success;}

3. Modify on the basis of the above topic: Declare member functions in a class and define member functions outside of the class

Code implementation:

1#include <iostream>2#include <cstdlib>3#include <cassert>4 using namespacestd;5 class Time6 {7      Public:8         voidSet_time (Time &Time );9         voidShow_time (ConstTime &Time );Ten     Private: One         inthour; A         intminute; -         intsec; - }; the voidTime::set_time (Time &Time ) - { -cout<<"Hour (0-23):"<<Endl; -Cin>>Time.hour; +ASSERT (time.hour>0&&time.hour< -); -              +cout<<"minute (0-59):"<<Endl; ACin>>Time.minute; atASSERT (time.minute>0&&time.minute< -); -              -cout<<"second (0-59):"<<Endl; -Cin>>time.sec; -ASSERT (time.sec>0&&time.sec< -); - } in voidTime::show_time (ConstTime &Time ) - { tocout<<time.hour<<":"<<time.minute<<":"<<time.sec<<Endl; + } - intMain () the { * Time t; $ t.set_time (t);Panax Notoginseng t.show_time (t); -     returnexit_success; the}

4. Find the volume of three long Fang

Implementation code:

1#include <iostream>2#include <cstdlib>3#include <cassert>4 using namespacestd;5 classBox6 {7      Public:8Box (intLintWinth);9         DoubleVolume ()Ten         { One             returnlength*width*height; A         } -     Private: -         Doublelength; the         Doublewidth; -         Doubleheight; - }; - /* + *precondition:parameters must be number. - *postcondition:null + */ ABox::box (intLintWinth) at { -Length =l; -width =W; -Height =h; - } - intMain () in { -cout<<"Please enter the length, width and height of a rectangle:"<<Endl; to     intl,w,h; +Cin>>l>>w>>h; -ASSERT (l>0&&w>0&&h>0); the      * box Box (l,w,h); $cout<<"Box Volume:"<<box.volume () <<endl;Panax Notoginseng     returnexit_success; -}

C + + Example exercises (2)