codeup 1928

题目描述：

有两个日期，求两个日期之间的天数，如果两个日期是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

输出：

每组数据输出一行，即日期差值

样例输入：

20130101
20130105

样例输出：

5

#include<cstdio>
#include<iostream>
#include<cassert>
#include<string>
#include<fstream>

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}};
bool isLeap(int year){
	return (year % 100 != 0 && year % 4 == 0)||(year % 400 ==0);
}

int main(){
	
	ifstream in;
	in.open("test.txt");
	assert(in.is_open());
		
	int time1;
	int time2;
	while(!in.eof()){
		in >> time1;
		in >> time2;
	}
		
	if( time1 < time2) {
		int tem = time1;
		time1 = time2;
		time2 = tem;
	}
	
	int year1 = time1/10000, mon1 = time1 % 10000 / 100 , day1 = time1 % 100;
	int year2 = time2/10000, mon2 = time2 % 10000 / 100 , day2 = time2 % 100;

	int ans = 1;
	
	while( year1 > year2 || mon1 > mon2 || day1 > day2){
		day2++;
		if( day2 == month[mon2][isLeap(year2)] + 1){
			year2++;
			day2 = 1;
		}
		if( mon2 == 13){
			year2++;
			mon2 = 1;
		}
		ans++;
	}
	printf("%d\n",ans);
	
	return 0;
}

总结：边界条件一定要考虑清楚，否则功亏一篑。