[C language] Classic - Chronology

  . 1 #include <stdio.h>
   2  
  . 3  
  . 4  void WNL ( int Y);
   . 5  
  . 6  int main ( void )
   . 7  {
   . 8      int year;
   . 9      the printf ( " Please enter the year (greater than 1990): " );
 10      Scanf ( " D% " , & year);
 . 11      WNL (year); // call the function WNL calendar year print 
12 is      return  0 ;
 13 is  }
 14  
15  / * 
16  function: printing calendar
17  Function Parameters: Year
 18  Function Return Value: None
 19  Note: None
 20 is  * / 
21 is  void WNL ( int Y) {
 22 is      // . 1. 5. 4. 3 2. 6. 7. 8. 9. 11 10 12 is
 23 is      // 31 is 31 is 28 30 31 is 31 31 30 31 30 30 31 
24-      int Mon;
 25      int RN = 0 ;   // leap year mark 
26      int SUM = 0 ; // store the number of days 
27      int mon_one_day = 0 ; // know every month on the first day of the week 
28      int= mon_days 0 ; // total number of days each month storage 
29      int I, J = 0 ;
 30      int K = 0 ;
 31 is  
32      int W = (Y + (Y - . 1 ) / . 4 - (Y - . 1 ) / 100 + (Y - . 1 ) / 400 )% . 7 ; // record the required number of the week on the first day of the year 
33 is  
34 is      IF ((Y% . 4 == 0 ) && (Y% 100 ! = 0 ) || (Y% 400 == 0 ))  // leap 
35      {
 36          RN = . 1 ;
 37 [      }
 38 is  
39      for (Mon = . 1 ; Mon <= 12 is ; Mon ++ )
 40      {
 41 is  
42 is          SUM = 0 ;          // Total Days 
43 is          mon_days = 0 ;     // month days 
44 is          mon_one_day = 0 ; // first month, day of the week for recording the number of 
45          J = K;
 46 is  
47          Switch (Mon)// record the number of days per month of 
48          {
 49              Case  12 is : mon_days = 31 is ; BREAK ;
 50              Case  . 11 : mon_days = 30 ; BREAK ;
 51 is              Case  10 : mon_days = 31 is ; BREAK ;
 52 is              Case   . 9 : mon_days = 30 ; BREAK ;
 53 is              Case   . 8 : mon_days = 31 is ; BREAK ;
 54 is              Case   . 7 : mon_days = 31 is; break;
 55             case  6: mon_days = 30; break;
 56             case  5: mon_days = 31; break;
 57             case  4: mon_days = 30; break;
 58             case  3: mon_days = 31; break;
 59             case  2: mon_days = 28 + rn; break; //加上闰年（0或1）
 60             case  1: mon_days = 31; BREAK ;
 61 is          }
 62 is  
63 is          Switch (Mon) // number of records from January to the current month of days 
64          {
 65              Case  12 is : SUM + = 30 ;
 66              Case  . 11 : SUM + = 31 is ;
 67              Case  10 : SUM + = 30 ;
 68              Case   . 9 : SUM = + 31 is ;
 69              Case   . 8 : SUM = + 31 is ;
 70              Case   . 7 : SUM = + 30 ;
 71 is             Case   . 6 : SUM + = 31 is ;
 72              Case   . 5 : SUM + = 30 ;
 73 is              Case   . 4 : SUM + = 31 is ;
 74              Case   . 3 : SUM + = 28 + RN;
 75              Case   2 : SUM + = 31 is ;
 76              Case   . 1 : + = SUM 0 ;
 77          }
 78  
79          SUM = + (w to . 1 ); // subtracting day 
80          mon_one_day% = SUM . 7 ;  // weeks of each month on the first day of 
81  
82          / * ******** print ********** * / 
83          printf ( " / ********* **% d month ************** / \ R & lt \ n- " , Mon);
 84          the printf ( "   MTWTFSS \ R & lt \ n- " );
 85  
86  
87          for (I = 0 ; I <mon_one_day; I ++)   // align 
88          {
 89              the printf ( "     " );
 90              J ++ ;
 91 is          }
 92  
93          for(I = . 1 ; I <= mon_days; I ++ )
 94          {
 95              the printf ( " % 4D " , I); // Align 
96              J ++ ;
 97              IF (J% . 7 == 0 )     // every 7 days for line 
98              {
 99                  the printf ( " \ R & lt \ n- " );
 100              }
 101          }
 102  
103          the printf ( " \ R & lt \ n- " );
 104      }
105 }

Note: This program can be used as the basic C language statements job title

Note: switch statement if there is no break, after completion of the operation will continue to run after the jump statement statement, for example,

run:

　　int i = 1，sum = 0；

  Switch (I) { 
  Case 1: = SUM + 1 ; 
  Case 2: = SUM + 2 ; 
  Case 3: SUM + = 3 ; 
} 
　　after, sum is 0 + 2 + 1 + 3 = 6