C code

gistfile1.c

#include "stdio.h"
 
int main(void) {
    int leap_year(int y)
      {  
      int is_leap;
      is_leap = (y % 400 == 0) || 
        ((y % 4 == 0) && !(y % 100 == 0));
      return is_leap;
      }
    int how_many_days(int year, int month)
      {
      int days;
      if (year < 0 || month < 1 || month > 12)
        return 0;
      switch (month) 
        {
        case 1: case 3: case 5: case 7: 
        case 8: case 10: case 12:
          days = 31;
          break;
        case 4: case 6: case 9: case 11: 
          days = 30;
          break;
        case 2:
          days = leap_year(year)? 29 : 28; 
          break;
        default:
          days = 0;
        }
      return days;
    }
    scanf("%d %d", &inputY, &inputD);//第一行input:元旦時星期幾，範例 2015 4
    int count(int inputY, inputD)
      int targetM, targetD;
      scanf("%d %d", &targetM, &targetD); //第二行input， 抓目標日期，範例 11 7
      int day = 1;//初始化
      int month = 1;//初始化
      int today = inputD;
      while(day < 32)//到兩個日期一樣時就會跳出的loop
        today ++;
        if (today >= 6)//如果一周到週六，重新開始
            today = 0;
        day++;
		/*
        if (day ==  how_many_days(inputY,month))//到了月底，進下個月
   	        day=1;
            month++; 
 		*/
      printf("%d", today);//最後丟出（過了多少天）今天星期幾
    return 0;
}