Question

In C Programming

Easter Sunday is the first Sunday after the first full moon of spring. To compute the date, you can use this algorithm, invented by the mathematician Carl Friedrich Gauss in 1800:
        1. Let y be the year (such as 1800 or 2001)
        2. Divide y by 19 and call the remainder a. Ignore the quotient.
        3. Divide y by 100 to get a quotient b and a remainder c.
        4. Divide b by 4 to get a quotient d and a remainder e.
        5. Divide 8 * b + 13 by 25 to get a quotient g. Ignore the remainder.
        6. Divide 19 * a + b - d - g + 15 by 30 to get a remainder h. Ignore the quotient.
        7. Divide c by 4 to get a quotient j and a remainder k.
        8. Divide a + 11 * h by 319 to get a quotient m. Ignore the remainder.
        9. Divide 2 * e + 2 * j - k - h + m + 32 by 7 to get a remainder r. Ignore the quotient.
        10. Divide h - m + r + 90 by 25 to get a quotient n. Ignore the remainder.
        11. Divide h - m + r + n + 19 by 32 to get a remainder p. Ignore the quotient.
The Easter faqs on day p of month n. For example, if y is 2001:
a = 6
b = 20, c = 1
d = 5, e = 0
g = 6
h = 18
j= 0, k = 1
m = 0
r = 6
n = 4
p = 15
Therefore, in 2001, Easter Sunday fell on April 15. Write a program that prompts the user for a year and prints out the month and day of Easter Sunday.

Answer 1

Please find the C code below.

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#include <stdio.h>
int main()
{
int y;
printf("Enter the year : ");
scanf("%d",&y);
int a = y%19; //Divide y by 19 and call the remainder a. Ignore the quotient.
int b = y/100; //Divide y by 100 to get a quotient b .
int c = y % 100; //Divide y by 100 to get a remainder c.
int d = b / 4; //Divide b by 4 to get a quotient d.
int e = b % 4; //Divide b by 4 to get a remainder e.
int g = (8*b + 13) / 25; // Divide 8 * b + 13 by 25 to get a quotient g. Ignore the remainder.
int h = (19 *a + b - d-g +15) % 30 ; //Divide 19 * a + b - d - g + 15 by 30 to get a remainder h. Ignore the quotient.
int j = c /4 ; //Divide c by 4 to get a quotient j.
int k = c % 4; //Divide c by 4 to get a remainder k.
int m = (a + 11 * h) / 319 ; // Divide a + 11 * h by 319 to get a quotient m. Ignore the remainder.
int r = ( 2 * e + 2 *j - k - h + m + 32) % 7;//Divide 2 * e + 2 * j - k - h + m + 32 by 7 to get a remainder r. Ignore the quotient.
int n = (h - m + r + 90) / 25;//Divide h - m + r + 90 by 25 to get a quotient n. Ignore the remainder.
int p = (h - m + r + n + 19) % 32;//Divide h - m + r + n + 19 by 32 to get a remainder p. Ignore the quotient.
switch(n) { //switch function to find the month
       case 1 : printf("In %d , Easter Sunday fell on January %d",y,p); break;
       case 2 : printf("In %d , Easter Sunday fell on February %d",y,p); break;
       case 3 : printf("In %d , Easter Sunday fell on March %d",y,p); break;
       case 4 : printf("In %d , Easter Sunday fell on April %d",y,p);break;
       case 5 : printf("In %d , Easter Sunday fell on May %d",y,p); break;
       case 6 : printf("In %d , Easter Sunday fell on June %d",y,p); break;
       case 7 : printf("In %d , Easter Sunday fell on July %d",y,p); break;
       case 8 :printf("In %d , Easter Sunday fell on August %d",y,p); break;
       case 9 : printf("In %d , Easter Sunday fell on September %d",y,p); break;
       case 10 : printf("In %d , Easter Sunday fell on October %d",y,p); break;
       case 11 : printf("In %d , Easter Sunday fell on November %d",y,p); break;
       case 12 : printf("In %d , Easter Sunday fell on December %d",y,p); break;
       default : printf("Invalid month.");
   }   
return 0;
}
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Please refer to the screenshot for the code below

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output screenshot

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