日期问题

日期问题的常规操作

/*给出年份m和一年中的第几天，算出第几天是几月几号，按照yyyy-mm-dd格式打印*/
#include <stdio.h>

int IsYeap(int year){
    if(year%400==0||(year%100!=0&&year%4==0)) return 1;
    else return 0;
}
int DayOfMonth[13][2]={
    0,0,
    31,31,
    28,29,
    31,31,
    30,30,
    31,31,
    30,30,
    31,31,
    31,31,
    30,30,
    31,31,
    30,30,
    31,31
};

int main(){
    int m,n;
    while(scanf("%d %d",&m,&n)!=EOF){
        int month=0;
        for(int i=1;i<=12;i++){
            if(n>DayOfMonth[i][IsYeap(m)]){
                n=n-DayOfMonth[i][IsYeap(m)];
            }else{
                month=i;
                break;
            }
        }
        //c语言的格式输出好处
        printf("%d-%02d-%02d\n",m,month,n);
    }
}

日期问题相差天数

//太复杂的做法    
string s1,s2,tmp;
    cin>>s1>>s2;
    if(s1>s2){
        tmp=s1;
        s1=s2;
        s2=tmp;
    }
    string yearS1=s1.substr(0,4),monS1=s1.substr(4,2),dayS1=s1.substr(6,2);
    string yearS2=s2.substr(0,4),monS2=s2.substr(4,2),dayS2=s2.substr(6,2);
    int year1,mon1,day1,year2,mon2,day2;
    year1=atoi(yearS1.c_str());
    mon1=atoi(monS1.c_str());
    day1=atoi(dayS1.c_str());
    year2=atoi(yearS2.c_str());
    mon2=atoi(monS2.c_str());
    day2=atoi(dayS2.c_str());
    cout << year1 <<" "<< mon1 <<" "<<day1<< endl;

//机制简便的处理办法
#include <cstdio>
int month[13][2]={{0,0},{31,31},{28,29},{31,31},{30,30},{31,31},
{30,30},{31,31},{31,31},{30,30},{31,31},{30,30},{31,31}};
int main()
{
    int time1,y1,m1,d1;
    int time2,y2,m2,d2;
    while(scanf("%d%d",&time1,&time2)!=EOF)
    {
        if(time1>time2)
        {
            int temp=time1;
            time1=time2;
            time2=temp;
        }
        y1=time1/10000;m1=time1%10000/100;d1=time1%100;
        y2=time2/10000;m2=time2%10000/100;d2=time2%100;
        int ans=1;
        while(y1<y2||m1<m2||d1<d2)
        {
            d1++;
            if(d1==month[m1][(y1%4==0&&y1%100!=0)||(y1%400==0)]+1)
            {   
                m1++;
                d1=1;
            }
            if(m1==13)
            {
                y1++;
                m1=1;
            }
            ans++;
        }
        printf("%d\n",ans);
    }
    return 0;
}

利用日期差值求星期

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
int month[13][2]={{0,0},{31,31},{28,29},{31,31},{30,30},{31,31},
{30,30},{31,31},{31,31},{30,30},{31,31},{30,30},{31,31}};
char weekname[8][15]={"","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"};
char monthname[13][15]={"","January","February","March","April","May","June","July","August","September","October","November","December"};
int StringtoNumber(char a[])
{
    for(int i=1;i<13;++i)
        if(strcmp(a,monthname[i])==0)
            return i;
}
void NumbertoString(char a[],int ans,int flag)
{
    int b;
    if(flag==0)
        b=6-ans%7;
    else
        b=(ans+6)%7;
    if(b==0)
        b=7;
    strcat(a,weekname[b]);
}
int main()
{ 
    char m[20],week[20];
    int y1,m1,d1;
    while(scanf("%d %s %d",&d1,m,&y1)!=EOF)
    {
        int y2=2018,m2=1,d2=6,flag=0,ans=0;
        m1=StringtoNumber(m);
        memset(m,'\0',sizeof(m));
        memset(week,'\0',sizeof(week));
        if(y1>y2||(y1==y2&&m1>m2)||(y1==y2&&m1==m2&&d1>d2))
        {
            flag=1;
            swap(y1,y2);
            swap(m1,m2);
            swap(d1,d2);
        }
        while(y1<y2||m1<m2||d1<d2)
        {
            d1++;
            if(d1==month[m1][(y1%4==0&&y1%100!=0)||(y1%400==0)]+1)
            {   
                m1++;
                d1=1;
            }
            if(m1==13)
            {
                y1++;
                m1=1;
            }
            ans++;
        }
        NumbertoString(week,ans,flag);
        printf("%s\n",week);
    }
    return 0;
}