今年过去了多少天？（switch）

//今年已经过去了几天？
#include <stdio.h>
int monthday(int year,int month){
    switch(month){
    case 1:return 31;
    case 2:
    if ((year % 4 == 0 && year % 100 != 0)||year % 400 == 0)
	{
		return 29;
	}
	else
	{
		return 28;
	}break;
    case 3:return 31;
    case 4:return 30;
    case 5:return 31;
    case 6:return 30;
    case 7:return 31;
    case 8:return 31;
    case 9:return 30;
    case 10:return 31;
    case 11:return 30;
    case 12:return 31;
    default:return 0;
    }
}
int main(){
    int year,month,day;
    scanf("%d %d %d",&year,&month,&day);
    int i=1;
    int sum=day;
    for(i=1;i<=month;i++){
        sum+=monthday(year,i-1);
    }
    if(sum==1){
        printf("So far 1 day");
    }
    else{
        printf("So far %d days",sum);
    }
}