日期差值 （水）

#include<bits/stdc++.h>
using namespace std;
#define ll long long
const double pi=acos(-1.0);
const double eps=1e-8;
const int maxn=100005;
int days[2][13]= {{0,31,28,31,30,31,30,31,31,30,31,30,31},{0,31,29,31,30,31,30,31,31,30,31,30,31}};
bool check(int y)
{
    if(y%400==0||y%100!=0&&y%4==0)
    {
        return 1;
    }
    return 0;
}
int get_sum(int y,int m,int d)
{
    int ans=0;
    if(check(y))
    {
        for(int i=1; i<m; i++)
        {
            ans+=days[1][i];
        }
    }
    else
    {
        for(int i=1; i<m; i++)
        {
            ans+=days[0][i];
        }
    }
    ans+=d;
    return ans;
}
int main()
{
    int x,y;
    while(~scanf("%d%d",&x,&y))
    {
        int a=x%10;
        int b=x/10%10;
        int c=x/100%10;
        int d=x/1000%10;

        int e=x/10000%10;
        int f=x/100000%10;
        int g=x/1000000%10;
        int h=x/10000000%10;
        int y1=h*1000+g*100+f*10+e;
        int m1=d*10+c;
        int d1=b*10+a;

        int aa=y%10;
        int ba=y/10%10;
        int ca=y/100%10;
        int da=y/1000%10;

        int ea=y/10000%10;
        int fa=y/100000%10;
        int ga=y/1000000%10;
        int ha=y/10000000%10;
        int y2=ha*1000+ga*100+fa*10+ea;
        int m2=da*10+ca;
        int d2=ba*10+aa;
//        printf("%04d%02d%02d\n",y1,m1,d1);
//         printf("%04d%02d%02d\n",y2,m2,d2);
        int sum1=get_sum(y1,m1,d1);
        int sum2=get_sum(y2,m2,d2);
        int ans=0;
        if(y1==y2)
        {
            printf("%d\n",abs(sum1-sum2)+1);
        }
        else
        {
            if(y2<y1)
            {
                if(check(y2))
                {
                    ans+=366-sum2+1;
                    y2++;
                }
                else
                {
                    ans+=365-sum2+1;
                    y2++;
                }
                while(y1!=y2)
                {
                    if(check(y2))
                    {
                        ans+=366;
                    }
                    else ans+=365;
                    y2++;

                }
                ans+=sum1;
            }
            else
            {
                if(check(y1))
                {
                    ans+=366-sum1+1;
                    y1++;
                }
                else
                {
                    ans+=365-sum1+1;
                    y1++;
                }
                while(y1!=y2)
                {
                    if(check(y1))
                    {
                        ans+=366;
                    }
                    else ans+=365;
                    y1++;

                }
                ans+=sum2;
            }
            printf("%d\n",ans);
        }
    }
    return 0;
}