华为机试题——HJ73 计算日期到天数转换

描述

根据输入的日期，计算是这一年的第几天。

保证年份为4位数且日期合法。

进阶：时间复杂度：O(n)\O(n) ，空间复杂度：O(1)\O(1) 

输入描述：

输入一行，每行空格分割，分别是年，月，日

输出描述：

输出是这一年的第几天

示例1

输入：

2012 12 31

复制输出：

366

复制

示例2

输入：

1982 3 4

复制输出：

63

#include <iostream>


//2012 12 31
int date2day(std::string date)
{
    int count = 0;
    int len = date.length();
    // std::cout << date << std::endl;
    int index = date.find(' ');
    int year = atoi(date.substr(0, index).c_str());
    date = date.substr(index + 1, len - index - 1);
    index = date.find(' ');
    int month = atoi(date.substr(0, index).c_str());
    date = date.substr(index + 1, len - index - 1);
    index = date.find(' ');
    int day = atoi(date.substr(0, index).c_str());

    if((year % 4 == 0 && year % 100 != 0) || (year % 100 == 0 && year % 400 == 0))
    {
        switch (month)
        {
        case 1:
            count = day;
            break;
        case 2:
            count = day + 31;
            break;
        case 3:
            count = day + 60;
            break;
        case 4:
            count = day + 91;
            break;
        case 5:
            count = day + 121;
            break;
        case 6:
            count = day + 152;
            break;
        case 7:
            count = day + 182;
            break;
        case 8:
            count = day + 213;
            break;
        case 9:
            count = day + 244;
            break;
        case 10:
            count = day + 274;
            break;
        case 11:
            count = day + 305;
            break;
        case 12:
            count = day + 335;
            break;
        
        default:
            break;
        }
    }
    else
    {
        switch (month)
        {
        case 1:
            count = day;
            break;
        case 2:
            count = day + 31;
            break;
        case 3:
            count = day + 59;
            break;
        case 4:
            count = day + 90;
            break;
        case 5:
            count = day + 120;
            break;
        case 6:
            count = day + 151;
            break;
        case 7:
            count = day + 181;
            break;
        case 8:
            count = day + 212;
            break;
        case 9:
            count = day + 243;
            break;
        case 10:
            count = day + 273;
            break;
        case 11:
            count = day + 304;
            break;
        case 12:
            count = day + 334;
            break;
        
        default:
            break;
        }
    }

    return count;
}

int main()
{
    std::string date;
    while(getline(std::cin, date))
    {
        std::cout << date2day(date) << std::endl;
    }

    return 0;
}