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cs:c_language:leap_year

# Leap Year

Concepts:
If statement and boolean expressions

Text:
Given a year (an integer number), say if it is a leap year. A leap year is a year:

• divisible by 4
• but not by 100
• with the exception of the years divisible by 400, which are leap years

Examples: 1996, 2000 and 2100 are leap years; instead 2015, 1900 and 2100 are not leap years.

Solution:

leap year.c
/*
Given a year (an integer number), say if it is a leap year.
A leap year is divisible by 4, but not by 100.
An exception are the years divisible by 400, which are leap years.
*/

#include <stdio.h>

int main(void){
int bis=0;
int year;

printf("Insert an year: ");
scanf("%d", &year);

/* First solution: base on a support varible bis */
if ( year%4==0 )   /* divisible by 4 */
bis=1;

if ( year%100==0 ) /* but not by 100 */
bis=0;

if ( year%400==0 ) /* but year divisible by 400 are leap years */
bis=1;

if ( bis==1 ){
printf("%d is a leap year\n", year);
}else{
printf("%d is not a leap year\n", year);
}

/* Second solution: using a boolean expression */
if ( (year%4==0 && year%100!=0) || year%400==0 ){
printf("%d is a leap year\n", year);
}else{
printf("%d is not a leap year\n", year);
}

return 0;
}

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