帮忙解几道很简单的c++题

来源:百度知道 编辑:UC知道 时间:2024/05/26 12:12:36
1)把一张一元的纸币换成1分、2分、5分的硬币,假如每种至少一枚,问有多少换法?
2)编写一个程序,将用户输入的数字(0-6)换成相应的星期值输出。如用户输入3则输出“today is wed"用户输入0,则显示"today is sun",如果不正确,则显示"I don't know what you mean"
3)编写一个程序,利用下列公式求m的值。
m/4=1-1/3+1/5-1/7+(1/4n-3)-(1/4n-1) n=2000
用简单的c++语言编写,易懂!!回答满意本人再追加20分!!!!!!!!!!

第一题:
#include<iostream>
using namespace std;

int main()
{
int count=0;
for(int i=0; i<=100; i++)
for(int j=0; j<=50; j++)
for(int k=0; k<=20; k++)
{
if(i+2*j+5*k==100)count++;
}
cout<<count;
return 0;
}
第二题:
#include<iostream>
using namespace std;
int main()
{
int n;
cin>>n;
switch(n)
{
case 0: cout<<"today is sun"<<endl;break;
case 1: cout<<"today is mon"<<endl;break;
case 2: cout<<"today is tue"<<endl;break;
case 3: cout<<"today is wed"<<endl;break;
case 4: cout<<"today is thu"<<endl;break;
case 5: cout<<"today is fri"<<endl;break;
case 6:cout<<"today is sat"<<endl;break;
default:cout<<"I don't