华为机试 HJ73题解 | #计算日期到天数转换#

#include <iostream>
#include <bits/stdc++.h>
using namespace std;

int GetDaysOfYear(int year, int month, int day) {
    int days = 0;
    bool isLeapYear = false;    // 是否为闰年
    if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)) {
        // 判断是否为闰年（能被4整除或者能被100整除但不能被400整除，则为闰年。闰年有366天；平年为365天）
        isLeapYear = true;
    } else {
        isLeapYear = false;
    }
    switch (month) {
        case 1:
            days = day;
            break;
        case 2:
            days = 31 + day;
            break;
        case 3:
            days += 31 + (isLeapYear ? 29 : 28) + day;
            break;
        case 4:
            days += 31 + (isLeapYear ? 29 : 28) + 31 + day;
            break;
        case 5:
            days += 31 + (isLeapYear ? 29 : 28) + 31 + 30 + day;
            break;
        case 6:
            days += 31 + (isLeapYear ? 29 : 28) + 31 + 30 + 31 + day;
            break;
        case 7:
            days += 31 + (isLeapYear ? 29 : 28) + 31 + 30 + 31 + + 30 + day;
            break;
        case 8:
            days += 31 + (isLeapYear ? 29 : 28) + 31 + 30 + 31 + +30 + 31 + day;
            break;
        case 9:
            days += 31 + (isLeapYear ? 29 : 28) + 31 + 30 + 31 + +30 + 31 + 31 + day;
            break;
        case 10:
            days += 31 + (isLeapYear ? 29 : 28) + 31 + 30 + 31 + +30 + 31 + 31 + 30 + day;
            break;
        case 11:
            days += 31 + (isLeapYear ? 29 : 28) + 31 + 30 + 31 + +30 + 31 + 31 + 30 + 31 +
                    day;
            break;
        case 12:
            days += 31 + (isLeapYear ? 29 : 28) + 31 + 30 + 31 + +30 + 31 + 31 + 30 + 31 +
                    30 + day;
            break;
        default:
            break;
    }
    return days;
}

int main() {
    int year, month, day;
    while (cin >> year >> month >> day) { // 注意 while 处理多个 case
        cout << GetDaysOfYear(year, month, day) << endl;
    }
}