日期类问题
文章根据王道机试书进行学习。
闰年的判断规则
当年数不能被100整除时若其能被4整除则为闰年,或者其能被400整除也为闰年,闰年二月29天,平年二月28天
即Year%100!=0 &&Year%4==0 ||Year%400==0
日期差值问题
问题描述:
有两个日期,求两个日期之间的天数,如果两个日期时连续的我们规定他们之间的天数为两天。
输入:
有多组数据,每组数据有两行,分别表示两个日期,形式为YYYYMMDD
示例代码:
(思想是把问题统一到与原点日期0000年1月1日时间差的计算上)
#include <stdio.h>
#define ISYEAP(x) x%100!=0&&x%4==0||x%400==0?1:0
//定义宏判断是否闰年
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} ;
struct Data{
int Day;
int Month;
int Year;
void nextDay(){
Day++;
if(Day>dayOfMonth[Month][ISYEAP(Year)]){
Day=1;
Month++;
if(Month>12){
Month=1;
Year++;
}
}
}
};
int buf[5001][13][32];//保存预处理的天数
int Abs(int x){
return x<0?-x:x;
}
int main(){
Data tmp;
int cnt=0;
tmp.Day=1;
tmp.Month=1;
tmp.Year=0;
while(tmp.Year!=5001){
buf[tmp.Year][tmp.Month][tmp.Day]=cnt;
tmp.nextDay();
cnt++;
}
int d1,m1,y1;
int d2,m2,y2;
while(scanf("%4d%2d%2d",&y1,&m1,&d1)!=EOF){
scanf("%4d%2d%2d",&y2,&m2,&d2);
printf("%d\n",Abs((buf[y2][m2][d2]-buf[y1][m1][d1]))+1);
}
return 0;
}
星期几判断问题
样例输入:
9 October 2001
14 October 2001
样例输出:
Tuesday
Sunday
示例代码:
#include <stdio.h>
#include <string.h>
#define ISYEAP(x) x%100!=0&&x%4==0||x%400==0?1:0
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};
struct Data{
int Day;
int Month;
int Year;
void nextDay(){
Day++;
if(Day>dayOfMonth[Month][ISYEAP(Year)]){
Day=1;
Month++;
if(Month>12){
Month=1;
Year++;
}
}
}
};
int buf[5001][13][32];
char monthName[13][20]={
"",
"January",
"February",
"March",
"April",
"May",
"June",
"July",
"August",
"September",
"October",
"November",
"December"};
char weekName[7][20]={
"Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"};
int main(){
Data tmp;
int cnt=0;
tmp.Day=1;
tmp.Month=1;
tmp.Year=0;
while(tmp.Year!=5001){
buf[tmp.Year][tmp.Month][tmp.Day]=cnt;
tmp.nextDay();
cnt++;
}
int d,m,y;
char s[20];
while(scanf("%d%s%d",&d,s,&y)!=EOF){
for(m=1;m<=12;m++){
if(strcmp(s,monthName[m])==0){
break;
}
}
int days=buf[y][m][d]-buf[2019][7][12];//2019年7月12日是周五
days+=5;//周五下标是5
printf("%s\n",weekName[(days%7+7)%7]);
}
return 0;
}
总结
宏定义的函数形式如:#define ISYEAP(x) x%100!=0&&x%4==0||x%400==0?1:0
strcmp()字符串比较,当为0时候表示相同