帮别人写的一个简单计算器

#include<stdio.h>
#include<iostream>
#include<math.h>
#include<algorithm>
using namespace std;
int mean(void)              //定义菜单函数
{
   
    int op=0;
    printf("/_________________\n");
    printf("1-----与操作\n");//字就懒得打了。
    printf("2-----\n");
    printf("3-----\n");
    printf("4-----\n");
    printf("5-----\n");
    printf("6-----\n");
    printf("7-----\n");
    printf("8-----\n");
    printf("9-----\n");
    printf("10-----\n");
    printf("100-----\n");
    printf("_________________\n");
    printf("请输人功能选择:");
    scanf("%d",&op);
    printf("1-----与操作\n");
    printf("2-----\n");
    printf("3-----\n");
    printf("4-----\n");
    printf("5-----\n");
    printf("6-----\n");
    printf("7-----\n");
    printf("8-----\n");
    printf("9-----\n");
    printf("10-----\n");
    printf("100-----\n");
    return op;
}
bool Function1(bool a,bool b)
{
   
    return a&b;
}
bool Function2(bool a,bool b)
{
   
    return a||b;
}
bool Function3(bool a)
{
   
    a=!a;
    return a;
}
bool Function4(bool a,bool b)
{
   
    return a&b;
}
double Function5(int a)
{
   
   a=abs(a);
    return a;
}
int Function6(int a,int b)
{
   
    return a%b;
}
int Function7(int a,int b)
{
   
    return (a+b)/2;
}
int Function8(int n)
{
   
    int sum=0;
    for(int i=1; i<=n; i++)
        sum+=i;
    return sum;
}
int Function9(int n)
{
   
    int sum=1;
    for(int i=1; i<=n; i++)
        sum*=i;
    return sum;
}
int Function10(double n)
{
   
    return n;
}
int main(void)
{
   
    int choice;
    bool boola,boolb,boolresult;
    int inta,intb,intresult;
    double doublea,doubleb,doubleresult;
    while(1)
    {
   
        int op = mean();
        if(100==op)
        {
   
            break;
        }
        switch(op)
        {
   
        case 1:{
   
            cin>>boola>>boolb;
            doubleresult = Function1(boola,boolb);
            break;
        }
        case 2:{
   
            cin>>boola>>boolb;
            doubleresult = Function2(boola,boolb);
            break;
        }
        case 3:
            cin>>boolresult;
            doubleresult = Function3(boolresult);
            break;
        case 4:{
   
            cin>>boola>>boolb;
            doubleresult = Function4(boola,boolb);
            break;
        }
        case 5:{
   
            cin>>inta;
            doubleresult = Function5(inta);
            break;
        }
        case 6:{
   
            cin>>doublea>>doubleb;
            doubleresult = Function6(doublea,doubleb);
        }
        case 7:{
   
            cin>>inta>>intb;
            doubleresult = Function7(inta,intb);
            break;
        }
        case 8:{
   
            cin>>inta;
            doubleresult = Function8(inta);
            break;
        }
        case 9:{
   
            cin>>inta;
            doubleresult = Function9(inta);
            break;
        }
        case 10:{
   
            cin>>doubleresult;
            doubleresult =Function10(doubleresult);
            break;
        }
        default:{
   
            cout<<"错误";
        }
        }
        printf("doubleresult =%.3lf\n",doubleresult);
    }
    return 0;
}