定义枚举型Month，其中的枚举项以英文月份名January、February等表示；实现如下的getDays()函数；使得下述程序能正确打印指定年月的天数。 说明：函数返回指定年月的天数，getDays(2022,April)应返回30，请注意区分闰年。 函数接口定义： int getDays(int year, enum Month m); 裁判测试程序样例： #include <stdio.h> #include <stdbool.h> bool isLeapYear(const int year){ //四年一闰，百年不闰，四百年又闰 if (year%400==0) return true; else if (year%100==0) return false; else if (year%4==0) return true; else return false; } //此处定义enum Month枚举类型 //此处定义getDays()函数 int main() { printf("Year %d, Month %d: %d days\n",1600,(int)February,getDays(1600,February)); printf("Year %d, Month %d: %d days\n",2100,(int)February,getDays(2100,February)); printf("Year %d, Month %d: %d days\n",2104,(int)February,getDays(2104,February)); printf("Year %d, Month %d: %d days\n",1997,(int)February,getDays(1997,February)); printf("Year %d, Month %d: %d days\n",1996,(int)February,getDays(1996,February)); for (int i=1;i<=12;i++){ printf("Year %d, Month %d: %d days\n",5102,(enum Month)i,getDays(5102,(enum Month)i)); } return 0; } 输入样例： 输出样例： Year 1600, Month 2: 29 days Year 2100, Month 2: 28 days Year 2104, Month 2: 29 days Year 1997, Month 2: 28 days Year 1996, Month 2: 29 days Year 5102, Month 1: 31 days Year 5102, Month 2: 28 days Year 5102, Month 3: 31 days Year 5102, Month 4: 30 days Year 5102, Month 5: 31 days Year 5102, Month 6: 30 days Year 5102, Month 7: 31 days Year 5102, Month 8: 31 days Year 5102, Month 9: 30 days Year 5102, Month 10: 31 days Year 5102, Month 11: 30 days Year 5102, Month 12: 31 days

参考代码如下：

#include <stdio.h>
#include <stdbool.h>

enum Month {January = 1, February, March, April, May, June, July, August, September, October, November, December};

bool isLeapYear(const int year){
    //四年一闰，百年不闰，四百年又闰
    if (year%400==0)
        return true;
    else if (year%100==0)
        return false;
    else  if (year%4==0)
        return true;
    else
        return false;
}

int getDays(int year, enum Month m) {
    int days = 0;
    switch(m) {
        case January:
        case March:
        case May:
        case July:
        case August:
        case October:
        case December:
            days = 31;
            break;
        case April:
        case June:
        case September:
        case November:
            days = 30;
            break;
        case February:
            if (isLeapYear(year)) {
                days = 29;
            } else {
                days = 28;
            }
            break;
    }
    return days;
}

int main() {
    printf("Year %d, Month %d: %d days\n",1600,(int)February,getDays(1600,February));
    printf("Year %d, Month %d: %d days\n",2100,(int)February,getDays(2100,February));
    printf("Year %d, Month %d: %d days\n",2104,(int)February,getDays(2104,February));
    printf("Year %d, Month %d: %d days\n",1997,(int)February,getDays(1997,February));
    printf("Year %d, Month %d: %d days\n",1996,(int)February,getDays(1996,February));
    for (int i=1;i<=12;i++){
        printf("Year %d, Month %d: %d days\n",5102,(enum Month)i,getDays(5102,(enum Month)i));
    }
    return 0;
} 

输出结果：

Year 1600, Month 2: 29 days
Year 2100, Month 2: 28 days
Year 2104, Month 2: 29 days
Year 1997, Month 2: 28 days
Year 1996, Month 2: 29 days
Year 5102, Month 1: 31 days
Year 5102, Month 2: 28 days
Year 5102, Month 3: 31 days
Year 5102, Month 4: 30 days
Year 5102, Month 5: 31 days
Year 5102, Month 6: 30 days
Year 5102, Month 7: 31 days
Year 5102, Month 8: 31 days
Year 5102, Month 9: 30 days
Year 5102, Month 10: 31 days
Year 5102, Month 11: 30 days
Year 5102, Month 12: 31 days