golang99道练习题之04

1.题目：输入某年某月某日，判断这一天是这一年的第几天？

2.程序分析：以3月5日为例，应该先把前两个月的加起来，然后再加上5天即本年的第几天，

特殊情况，闰年且输入月份大于3时需考虑多加一天。

3..程序源代码：

package main

import "fmt"

func main() {
    var year, mouth, day, sum, feb int
    fmt.Println("请输入年月日：")
    fmt.Scan(&year, &mouth, &day)

    if (year%4 == 0 && year%100 != 0) || (year%400 == 0) {
        feb = 29
    } else {
        feb = 28
    }
    switch mouth {
    case 1:

        sum = 0 + day

    case 2:

        sum = 31 + day

    case 3:

        sum = feb + 31 + day

    case 4:

        sum = 31 + feb + 31 + day

    case 5:

        sum = 30 + 31 + feb + 31 + day

    case 6:

        sum = 31 + 30 + 31 + feb + 31 + day

    case 7:

        sum = 30 + 31 + 30 + 31 + feb + 31 + day

    case 8:

        sum = 31 + 30 + 31 + 30 + 31 + feb + 31 + day

    case 9:

        sum = 31 + 31 + 30 + 31 + 30 + 31 + feb + 31 + day

    case 10:

        sum = 30 + 31 + 31 + 30 + 31 + 30 + 31 + feb + 31 + day

    case 11:

        sum = 31 + 30 + 31 + 31 + 30 + 31 + 30 + 31 + feb + 31 + day

    case 12:

        sum = 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30 + 31 + feb + 31 + day

    }
    fmt.Printf("您输入的日期是这一年的第%d天", sum)
}