CodeForces 597A Divisibility

A. Divisibility

time limit per test
1 second

memory limit per test
256 megabytes

input
standard input

output
standard output

Find the number of k-divisible numbers on the segment [a, b].
In other words you need to find the number of such integer values x thata ≤ x ≤ b and x is
divisible by k.

Input

The only line contains three space-separated integers k, a and b (1 ≤ k ≤ 1018; - 1018 ≤ a ≤ b ≤ 1018).

Output

Print the required number.

Examples

input

1 1 10

output

10

input

2 -4 4

output

5

这个题要注意边界问题……

我分不太清边界怎么求，所以直接一步一步算了。有的人能写成一个式子不过我是做不到OTZ

#include<stdio.h>
int main()
{
__int64 k,a,b;
while(~scanf("%I64d%I64d%I64d",&k,&a,&b))
{
__int64 sum=0;
if(a<=0&&b>=0)
sum=-a/k+b/k+1;
if(a>0&&b>0)
{
if(a%k==0)
sum++;
sum+=b/k-a/k;
}
if(a<0&&b<0)
{
if(b%k==0)
sum++;
sum+=b/k-a/k;
}
printf("%I64d\n",sum);
}
return 0;
}