蓝桥杯官网 试题 PREV-227 历届真题 回文日期【第十一届】【决赛】【研究生组】【C++】【C】【Java】【Python】四种解法

为帮助大家能在6月18日的比赛中有一个更好的成绩，我会将蓝桥杯官网上的历届决赛题目的四类语言题解都发出来。希望能对大家的成绩有所帮助。

今年的最大目标就是能为【一亿技术人】创造更高的价值。

资源限制

内存限制：256.0MB C/C++时间限制：1.0s Java时间限制：3.0s Python时间限制：5.0s

#include 
#include 
#include 
#include 
#include 
using namespace std;
char a[10];
int yh,yab,flag;
bool pan_r(int y)
{
    if(y%4==0&&y%100!=0||y%400==0)
        return true;
    else
        return false;
}
void xiu()
{
    for(int i=7;i>0;i--)
    {
        if(a[i]==':')
        {
            a[i]='0';
            a[i-1]+=1;
        }
    }
}
void pan_ymd()
{
    xiu();
    int y,m,d;
    y=(a[0]-'0')*1000+(a[1]-'0')*100+(a[2]-'0')*10+a[3]-'0';  
    m=(a[4]-'0')*10+a[5]-'0';    
    d=(a[6]-'0')*10+a[7]-'0';   
    if(m!=2)     
    {
        if(m==1||m==3||m==5||m==7||m==8||m==10||m==12)
        {
            if(d==32)   
            {
                a[6]='0';
                a[7]='1';
                a[5]+=1;
                m+=1;
            }
        }
        else if(m==4||m==6||m==9||m==11)
        {
            if(d==31)   
            {
                a[6]='0';
                a[7]='1';
                a[5]+=1;
            }
        }
        if(m>12)
        {
            a[4]='0';
            a[5]='1';
            y+=1;
            int i=3;
            while(y)
            {
                a[i--]='0'+y%10;
                y/=10;
            }
        }
    }
    else
    {
        if(pan_r(y))
        {
            if(d==30)  
            {
                a[6]='0';
                a[7]='1';
                a[5]+=1;
            }
        }
        else
        {
            if(d==29)    
            {
                a[6]='0';
                a[7]='1';
                a[5]+=1;
            }
        }
    }
}
void pan_hw()
{
    int i,j,x=0,y=0,s;
    for(i=0;i<8;i++)
        x=x*10+(a[i]-'0');
    s=x;
    while(s)
    {
        y=y*10+s%10;
        s/=10;
    }
    if(x==y)
    {
        if(!flag)
        {
            yh=x;   
            flag=1;
        }
        if(a[0]==a[2]&&a[0]==a[5]&&a[0]==a[7]&&a[1]==a[3]&&a[1]==a[4]&&a[1]==a[6])
        {
            flag=2;
            yab=x;  
        }
    }
}
int main()
{
    int i,j;
   cin>>a;
    while(flag!=2)
    {
        a[7]+=1;    
        pan_ymd();
        pan_hw();
        if(flag==2)    
           cout< 
C 
#include
void year(int a);
int huiwen(int i);
int hefa(int data);
int ABAB(int j);
int main()
{
	int a;
	scanf("%d",&a);
	
	year(a);
	return 0;
}
void year(int a)
{

	int i,k=1,j,l=1;

	for(i=a/10000;i<9999;i++)
	{
		if(huiwen(i)&&k&&huiwen(i)>a)
		{
			printf("%dn",huiwen(i));
			k=0;
		}
	}
	for(j=a/1000000;j<100;j++)
	{
		if(ABAB(j)&&l&&ABAB(j)>a)
		{
			printf("%dn",ABAB(j));
			l=0;
		}
	}
}
int huiwen(int i)
{
	int a,b,c,d,data;
	a=i/1000;
	b=(i/100)%10;
	c=(i%100)/10;
	d=i%10;

	data=i*10000+1000*d+100*c+10*b+a;
	if(hefa(data))
	{
		
		return data;
		
	}
	return 0;
}
int ABAB(int j)
{
	int a,b,data;
	a=j/10;
	b=j%10;
	data=j*1000000+a+10*b+100*a+1000*b+10000*b+100000*a;
	if(hefa(data))
	{
		
		return data;
		
	}
	return 0;
} 
int hefa(int data)
{
	int year,mon,day;
	year=data/10000;
	mon=(data%10000)/100;
	day=data%100;
	if(mon==1)
	{
		if(day>0&&day<=31)
			return 1;
	}
	if(mon==3)
	{
		if(day>0&&day<=31)
			return 1;
	}
	if(mon==4)
	{
		if(day>0&&day<=30)
			return 1;
	}
	if(mon==5)
	{
		if(day>0&&day<=31)
			return 1;
	}
	if(mon==6)
	{
		if(day>0&&day<=30)
			return 1;
	}	
	if(mon==7)
	{
		if(day>0&&day<=31)
			return 1;
	}
	if(mon==8)
	{
		if(day>0&&day<=31)
			return 1;
	}
	if(mon==9)
	{
		if(day>0&&day<=30)
			return 1;
	}
	if(mon==10)
	{
		if(day>0&&day<=31)
			return 1;
	}
	if(mon==11)
	{
		if(day>0&&day<=30)
			return 1;
	}
	if(mon==12)
	{
		if(day>0&&day<=31)
			return 1;
	}
	if(mon==2)
	{
		if((year%100!=0&&year%4==0)&&year%400==0)
		{
			if(day>0&&day<=29)
				return 1;
		}
		else
		{
			if(day>0&&day<=28)
			 	return 1;
		}
	}
	return 0;
}
 
Java 
import java.io.*;
public class Main {
	
	public static void main(String args[]) throws Exception{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String s = br.readLine();
		String s1 = s.substring(0, 4);
		int yo = Integer.valueOf(s1);
		String t = null;
		String ab = null;
		for(int i=0;i<=9999-yo;i++) {//2020
			int y = yo+i;//2021
			int year = y;
			int a = y%10;//1
			y = y/10;//202
			int b = y%10;//2
			y = y/10;//20
			int c = y%10;//0
			y = y/10;//2
			int date = c*10+y;
			int month = a*10+b;
			if(date == 0) {
				continue;
			}
			if(month > 12 || month == 0) {
				continue;
			}
			if(month == 2) {
				if((year%4 == 0 && year%100 != 0)|| year%400 == 0) {
					if(date > 29) {
						continue;
					}
				}else {
					if(date > 28) {
						continue;
					}
				}
			}else if(date == 1 || date == 3 || date == 5 
					|| date == 7 || date == 8 || date == 10 || date == 12) {
				if(date > 31) {
					continue;
				}
			}else {
				if(date > 30) {
					continue;
				}
			}
			String dStr = String.valueOf(date);
			if(date < 10) {
				dStr = "0"+dStr;
			}
			String mStr = String.valueOf(month);
			if(month < 10) {
				mStr = "0"+mStr;
			}
			if(s.equals(year+mStr+dStr)){
				continue;
			}
			if(null == t) {
				t = year+mStr+dStr;
			}
			if(date == month) {
				ab = year+mStr+dStr;
				break;
			}
		}
		System.out.println(t);
		System.out.print(ab);
	}
	
}
 
Python 
n = int(input())
month_day = [0,31,28,31,30,31,30,31,31,30,31,30,31]
def is_valid(x):
    year, month, day = int(x[:4]), int(x[4:6]), int(x[6:])
    if month <  0 or month > 12:
        return False
    if day < 0 or (day > month_day[month] and month != 2):
        return False
    if month == 2:
        run = year % 400 == 0 or (year % 100 != 0 and year % 4 == 0)
        if day > month_day[month] + run:
            return False
    return True

def check_AB(x):
    a, b, c, d  = x[0], x[1], x[2], x[3]
    if a == c and b == d and a != b:
        return True
    return False

flag = 0
for i in range(n // 10000, 10000):
    s = str(i) + str(i)[::-1]
    int_s = int(s)
    if is_valid(s) and int_s > n and flag == 0:
        print(int_s)
        flag = 1
    if is_valid(s) and int_s > n and check_AB(s):
        print(int_s)
        break