题解 | 日期差值

#include <iostream>
#include<string>
using namespace std;

int mo1[13]={0,31,29,31,30,31,30,31,31,30,31,30,31};
int mo2[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
int main() {
    string s1,s2;
    int y1=0,y2=0,m1=0,m2=0,d1=0,d2=0;
    cin>>s1;
    cin>>s2;
    for(int i =0;i<=3;i++)//获取输入的年月日
    {
        char c1 = s1[i];
        char c2 = s2[i];
        y1 = y1*10+(c1 - '0');
        y2 = y2*10+(c2 - '0');
 //       cout<<c1-'0';
       
    }
    for(int i =4;i<=5;i++)
    {
        char c1 = s1[i];
        m1 =m1*10+ (c1 - '0');
        char c2 = s2[i];
        m2 =m2*10+ (c2 - '0');
    }
    for(int i =6;i<=7;i++)
    {
        char c1 = s1[i];
        d1 =d1*10+ (c1 - '0');
        char c2 = s2[i];
        d2 =d2*10+(c2 - '0');
    }
 //   cout<<y1<<" "<<m1<<" "<<d1<<endl;
    int cnt1=0,cnt2=0;
    if((y1%4==0&&y1%100!=0)||(y1%400==0))
    {
        for(int i=1;i<m1;i++)
        {
            cnt1 += mo1[i];
        }
        cnt1 +=d1;
    }
    else{
        for(int i=1;i<m1;i++)
        {
            cnt1 += mo2[i];
        }
        cnt1 +=d1;
    }
    if((y2%4==0&&y2%100!=0)||(y2%400==0))
        {
            for(int i=1;i<m2;i++)
            {
                cnt2 += mo1[i];
            }
            cnt2 +=d2;
        }
        else{
            for(int i=1;i<m2;i++)
            {
                cnt2 += mo2[i];
            }
            cnt2 +=d2;
        }
        int ans =0;
        if(y1==y2)
        {
            if(cnt1>cnt2)
            {
                ans = cnt1-cnt2;
                cout<<ans<<endl;
            }
            else {
                ans =cnt2-cnt1+1;
                cout<<ans<<endl;;
            }
        }
        else if(y1>y2){
            while(y1>y2)
            {
                if((y2%4==0&&y2%100!=0)||(y2%400==0))
                {
                    ans +=366;
                }
                else ans+=365;
                y2++;
            }
            cout<<ans+cnt1-cnt2+1;


        }
        else if(y1<y2){
            while(y1<y2)
            {
                if((y1%4==0&&y1%100!=0)||(y1%400==0))
                {
                    ans +=366;
                }
                else ans+=365;
                y1++;
            }
            cout<<ans+cnt2-cnt1+1;//计算差额
        }



}
// 64 位输出请用 printf("%lld")