平面分割问题，取石头游戏，一年的第几天，生日排序

平面分割问题

#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n,sum;
	while(scanf("%d",&n)==1)
	{
		sum=2;
		for(int i=1;i<=n;i++)
			sum=sum+2*(i-1);
		cout<<sum<<endl;
	}
	return 0;
}

取石头游戏

#include<bits/stdc++.h>
using namespace std;
int dp[10000001],n;//dp存的对于先手来说的赢输情况
int main()
{
	/*每次只能取1,3,7,8个*/
    dp[1]=1;//1,3,7,8这些情况下，先手第一次就取完全部，剩下0个，就直接先手胜
    dp[3]=1;
    dp[5]=1;//5是先手取3 后手1 先手1 最后剩0 ，先手胜
    dp[7]=1;
    dp[8]=1;
    while(cin>>n)
    {
        for(int i=9; i<=n; i++)
        {
            //i取完后剩下的能使后手失败那i状态就能胜
            if(!dp[i-1] || !dp[i-3] || !dp[i-7] || !dp[i-8])
                dp[i]=1;
            else
                dp[i]=0;
        }
        cout<<dp[n]<<endl;
    }
    return 0;
}

一年的第几天

#include<bits/stdc++.h>
using namespace std;
class base
{
public:
	int m_year=0;
	int m_month=0;
	int m_day=0;
};
void getSumDay(int year,int month,int day)
{
	int sum=0;
	int d=day;
	int monthday[12]={31,28,31,30,31,30,31,31,30,31,30,31};
	int m=month-1;
	for(int i=0;i<m;i++)
		sum+=monthday[i];
	if((year % 4 == 0) && (year % 100 != 0) || (year % 400 == 0))
	{
		if (month >= 3)
			cout<<sum+d+1;
		else
			cout<<sum+d;
	}
	else
		cout<<sum+d;
}
int main()
{
	base b;
	cin>>b.m_year>>b.m_month>>b.m_day;
	getSumDay(b.m_year, b.m_month, b.m_day); 
	return 0;
}

生日排序

#include<bits/stdc++.h>
using namespace std;
struct student
{
	string name;
	int m;
	int d;
}a[111];
int n,c=0;
bool cmp(student x,student y)
{
	if(x.m!=y.m)
		return x.m<y.m;
	if(x.d!=y.d)
		return x.d<y.d;
	if(x.name.size()!=y.name.size())
		return x.name.size()<y.name.size();
	return x.name<y.name;
}
int main()
{
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>a[i].name>>a[i].m>>a[i].d;	
	}
	sort(a,a+n,cmp);
	for(int i=0;i<n-1;i++)
	{
		if(a[i+1].m==a[i].m && a[i+1].d==a[i].d)
		{
			c++;
			cout<<a[i].m<<' '<<a[i].d<<' '<<a[i].name<<' ';
			while(a[i+1].m==a[i].m && a[i+1].d==a[i].d)
			{
				i++;
				cout<<a[i].name<<' ';
			}
			cout<<endl;
		}
	}
	if(c==0)
		cout<<"None";
    return 0;
}