1、组队

2、年号字符串

#include<iostream>
#include<map>
using namespace std;
 
int main(){
	map<int,char> m;
	for(int i= 1;i <= 26; i++){
		m[i]='A'+i-1;
	}
 	
 	int x =2019;
 	string re="";
 	int a= x/26;
 	int b = x%26;
 	
 	
 	if(a > 26){
 		cout <<  m[a/26] << m[a%26] << m[b];
	}else if(a < 26){
		cout << m[a] << m[b];
	}else{
		cout << m[a-1] <<m[26];
	}
	return 0;
	
}

答案：BYQ

3、数列求值

#include<iostream>
#include<map>
using namespace std;
const int MAXN = 20190324;
int dp[]
int main(){
	dp[1]=1;
	dp[2]=1;
	dp[3]=1;'
 
	for(int i = 4; i <= MAXN; i++){
			dp[i] = (dp[i-1]+dp[i-2]+dp[i-3]) %10000;
	}
	
	cout << dp[MAXN];
	return 0;
}

答案：4659