哈哈
素数判断
#include <iostream>
using namespace std;
int main()
int n;
cin>>n;
if(n<=1)
{
cout<<n<<"不是素数"<<endl;
return 0;
}
for(int i=2;i<n;i++)
{
if(n%i==0)
{
cout<<n<<"不是素数"<<endl;
return 0;
}
}
cout<<n<<"是素数"<<endl;
return 0;
闰年
#include <iostream>
using namespace std;
int main()
{
int N;
cin>>N;
if(N%400==0||N%100!=0&&N%4==0)
cout<<N<<"是闰年";
else
cout<<N<<"不是闰年";
return 0;
}
反序数是素数
#include <iostream>;
#include <cmath>;
using namespace std;
bool isprime(int N)
{
for(int i = 2; i < sqrt(N*1.0); i++)
{
if(N % i == 0)
{return false;}
}
return true;
}
int rev(int N)
{
int res = 0;
while(N > 0)
{
res = res*10 + N %10;
N = N/10;
}
return res;
}
int main()
{
int N = 107;
cin >> N;
//cout << 1;
for(int i = 100; i <= N; i++)
{
//cout << i << '\t' << isprime(i) << '\t' << rev(i) << '\t' << isprime(rev(i)) << '\n';
if((isprime(i) == isprime(rev(i))) &&
(isprime(i) == true))
{ cout << i << ' '; }
}
return 0;
}
读书问题
#include <iostream>
#include <string>
int main()
{
int N = 0;
std::cin >> N;
int res = 3;
for (int i = N; i > 1;i--)
{
res = (res + 2) * 2;
}
std::cout << res;
}
辛普森积分1
#include<bits/stdc++.h>
using namespace std;
double f(double x)
{ return sin(x)-cos(x)+x/3.0*x*x;}
int main()
{
double l,r;
cin>>l>>r;
cout<<f(r)-f(l);
return 0;
}
7.几何周长按面积排序
#include<bits/stdc++.h>
using namespace std;
int n;
double f(double x)
{
return pow(x,2);
}
struct node
{
int tp;
double x1,x2,x3,y1,y2,y3;
double zxx,zxy,ysx,ysy;
double xx,xy,r;
double c;
}a[100005];
bool cmp(node x,node y)
{
return x.c<y.c;
}
void print(double x)
{
long long a=(long long)x*10000,b=(long long)x*100000;
a=a%10;b=b%10;
if(a>0) cout<<fixed<<setprecision(4)<<x;
else if(a==0&&b==0) cout<<x;
else if(b>=5) cout<<fixed<<setprecision(4)<<x;
else cout<<x;
}
int main()
{
cin>>n;
string s;
for(int i=1;i<=n;i++)
{
node t;
cin>>s;
if(s=="CTriangle")
{
t.tp=1;
cin>>t.x1>>t.y1>>t.x2>>t.y2>>t.x3>>t.y3;
double dx1=t.x1-t.x2,dx2=t.x1-t.x3,dy1=t.y1-t.y2,dy2=t.y1-t.y3;
t.c=0.5*abs(dx1*dy2-dx2*dy1);
}
else if(s=="CCircle")
{
t.tp=2;
cin>>t.xx>>t.xy>>t.r;
t.c=3.1416*t.r*t.r;
}
else
{
t.tp=3;
cin>>t.zxx>>t.zxy>>t.ysx>>t.ysy;
t.c=abs(t.zxx-t.ysx)*abs(t.zxy-t.ysy);
}
a[i]=t;
}
sort(a+1,a+n+1,cmp);
for(int i=1;i<=n;i++)
{
if(a[i].tp==1)
{
cout<<"CTriangle{("<<a[i].x1<<", "<<a[i].y1<<"), ("<<a[i].x2<<", "<<a[i].y2<<"), ("<<a[i].x3<<", "<<a[i].y3<<")},area=";
}
else if(a[i].tp==2)
{
cout<<"CCircle{("<<a[i].xx<<", "<<a[i].xy<<"),"<<a[i].r<<"},area=";
}
else
{
cout<<"CRectangle{("<<a[i].zxx<<", "<<a[i].zxy<<"), ("<<a[i].ysx<<", "<<a[i].ysy<<")},area=";
}
print(a[i].c);
cout<<endl;
}
return 0;
}
数组求中位数和均值
#include<bits/stdc++.h>
using namespace std;
bool cmp(int a,int b)
{
return abs(a)>abs(b);
}
int main()
{
int a[105],n,ans,sum=0;
cin>>n;
for(int i=1;i<=n;i++) cin>>a[i],sum+=a[i];
sort(a+1,a+n+1);
if(n%2==0) cout<<(double)(a[n/2]+a[n/2+1])/2<<endl;
else cout<<a[n/2+1]<<endl;
cout<<(double)sum/n;
return 0;
}
