【codeforces】数学

B - B 使用long long
Time Limit:1000MS     Memory Limit:262144KB     64bit IO Format:%I64d
& %I64u
Submit Status Practice CodeForces
597A

Description

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 that a ≤ 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.

Sample Input

Input

1 1 10

Output

10

Input

2 -4 4

Output

5

分类讨论，数据类型别搞错就行了

#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
#define LL long long
using namespace std;
int main(){
LL k,a,b;
while(scanf("%lld%lld%lld",&k,&a,&b)!=EOF){
LL ans;
if(a>0&&b>0){
ans=b/k-(a-1)/k;
// printf("---\n");
}
else if(a<0&&b<0){
ans=abs(a)/k-abs(b+1)/k;
}
else{
ans=b/k+abs(a)/k+1;
}
printf("%lld\n",ans);
}
return 0;
}