https://www.luogu.com.cn/training/105#problems

P5735 【深基7.例1】距离函数

#include<bits/stdc++.h>
using namespace std;
double x[15],y[15];
double solve(double x,double y,double xx,double yy)
{
	return sqrt((x-xx)*(x-xx)+(y-yy)*(y-yy));
}
int main(void)
{
	for(int i=0;i<3;i++) cin>>x[i]>>y[i];
	double sum=0;
	sum+=solve(x[0],y[0],x[1],y[1]);
	sum+=solve(x[0],y[0],x[2],y[2]);
	sum+=solve(x[1],y[1],x[2],y[2]);
	printf("%.2lf",sum);
	return 0;
}

P5736 【深基7.例2】质数筛

#include<bits/stdc++.h>
using namespace std;
int a[105],n;
int main(void)
{
	cin>>n;
	for(int i=0;i<n;i++)
	{
		cin>>a[i];
		int flag=0;
		for(int j=2;j<=sqrt(a[i]);j++)
			if(a[i]%j==0) flag=1;
		if(!flag&&a[i]!=1) cout<<a[i]<<" ";
	}
	return 0;
}

P5737 【深基7.例3】闰年展示

#include<bits/stdc++.h> 
using namespace std;
int l,r;
vector<int>ve; 
int check(int x) 
{
	if(x%400==0||(x%4==0&&x%100!=0)) return 1;
	return 0;
}
int main(void)
{
	cin>>l>>r;
	for(int i=l;i<=r;i++)
		if(check(i)) ve.push_back(i);
	cout<<ve.size()<<endl;
	for(int i=0;i<ve.size();i++) cout<<ve[i]<<" ";
	return 0;
}

P5738 【深基7.例4】歌唱比赛

#include<bits/stdc++.h>
using namespace std;
int n,m,a[105];
double ans;
int main(void)
{
	cin>>n>>m;
	for(int i=1;i<=n;i++)
	{
		double sum=0;
		for(int j=0;j<m;j++) cin>>a[j],sum+=a[j];
		sort(a,a+m);
		ans=max(ans,(sum-a[0]-a[m-1])/(m-2));
	}
	printf("%.2lf",ans);
	return 0;
}

P5739 【深基7.例7】计算阶乘

#include<bits/stdc++.h> 
using namespace std;
int main(void)
{
	long long int n; cin>>n;
	long long int sum=1;
	while(n) sum*=n,n--;
	cout<<sum;
	return 0;
}