实验三

graph.cpp:

#include "graph.h" 
#include <iostream>
using namespace std;
Graph::Graph(char ch, int n): symbol(ch), size(n) {
}

void Graph::draw() 
{
    int length=2*size-1,i,j;
    for(i=1;i<=size;i++)
    {
        for(j=1;j<=size-i;j++)
            cout<<" ";
        for(j=1;j<=2*i-1;j++) 
            cout<<symbol;
        cout<<endl;
    }
}

graph.h:

#ifndef GRAPH_H
#define GRAPH_H

class Graph {
    public:
        Graph(char ch, int n); 
        void draw();
    private:
        char symbol;
        int size;
};


#endif

main.cpp:

#include <iostream>
#include "graph.h"
using namespace std;

int main() {
    Graph graph1('*',5);
    graph1.draw();
    
    system("pause");
    system("cls");
    
    Graph graph2('$',7);
    graph2.draw();
    
    return 0; 
}

项目三：

fraction.cpp    

#include "fraction.h"
#include<iostream>
using namespace std;

void fraction::add(fraction a , fraction b){
    fraction c;
    c.shang=a.shang*b.xia+b.shang*a.xia;
    c.xia=a.xia*b.xia;
    cout<<"两数相加："<<c.shang<<"/"<<c.xia<<endl;
}

void fraction::min(fraction a , fraction b){
    fraction c;
    c.shang=a.shang*b.xia-b.shang*a.xia;
    c.xia=a.xia*b.xia;
    cout<<"两数相减："<<c.shang<<"/"<<c.xia<<endl;
}

void fraction::mul(fraction a , fraction b){
    fraction c;
    c.shang=a.shang*b.shang;
    c.xia=a.xia*b.xia;
    cout<<"两数相乘："<<c.shang<<"/"<<c.xia<<endl;
}

void fraction::div(fraction a , fraction b){
    fraction c;
    c.shang=a.shang*b.xia;
    c.xia=a.xia*b.shang;
    cout<<"两数相除："<<c.shang<<"/"<<c.xia<<endl;
}

void fraction::compare(fraction a , fraction b){
    int c;
    c=a.shang*b.xia-b.shang*a.xia;
    if (c<0)
    cout<<"两数相较："<<a.shang<<"/"<<a.xia<<"<"<<b.shang<<"/"<<b.xia<<endl;
        else if (c>0)
        cout<<"两数相较："<<a.shang<<"/"<<a.xia<<">"<<b.shang<<"/"<<b.xia<<endl;
            else
            cout<<"两数相较："<<a.shang<<"/"<<a.xia<<"="<<b.shang<<"/"<<b.xia<<endl;
}

void fraction::show(){
    cout<<shang<<"/"<<xia<<endl;
}

#ifndef FRACTION_H
#define FRACTION_H
class fraction{
    public:
        fraction(int shang0 = 0 , int xia0 = 1):shang(shang0),xia(xia0){}
        void add(fraction a,fraction b);
        void min(fraction a,fraction b);
        void mul(fraction a,fraction b);
        void div(fraction a,fraction b);
        void compare(fraction a,fraction b);
        void show();
    private:
        int shang;
        int xia;
};

#endif

#include<iostream>
#include"Fraction.h"
using namespace std;
int main(){
    fraction a;
    a.show();
    fraction b(3,4);
    b.show();
    fraction c(5);
    c.show();
    fraction e;
    e.add(b,c);
    e.min(b,c);
    e.mul(b,c);
    e.div(b,c);
    e.compare(b,c);
}