CodeForces - 597A Divisibility （模拟）

64bit IO Format: %I64d & %I64u

CodeForces - 597A

Divisibility

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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

Source

Testing Round #12

//题意：

给出k,a,b,让你求出在数列a---b之间有多少个数可以整除k.

//思路：

因为数比较大所以不能暴力模拟求解，所以得分情况考虑，主要分三段，

1、b<=0;

2、a<=0,b>=0

3、a>=0

将这三段考虑清楚就可以得出答案了，注意在情况1,3中要对0进行特殊判断。

#include<stdio.h>
#include<string.h>
#include<algorithm>
#define INF 0x3f3f3f3f
#define IN __int64
#define ll long long
#define N 10010
#define M 1000000007
#define PI acos(-1.0)
using namespace std;
int main()
{
	IN k,a,b;
	while(scanf("%I64d%I64d%I64d",&k,&a,&b)!=EOF)
	{
		IN l,r,rr;
		IN num;
		if(a<=0&&b<=0)
		{		
			IN kk=0;	
			if(b%k==0)
				kk=1;
			l=(-a)/k;
			r=(-b)/k;
			num=l-r+kk;
		}
		else if(a<=0&&b>=0)
		{
			l=(-a)/k;
			r=b/k;
			num=l+r+1;
		}
		else if(a>=0&&b>=0)
		{
			IN kk=0;
			if(a%k==0)
				kk=1;
			l=a/k;
			r=b/k;
			num=r-l+kk;
		}
		printf("%I64d\n",num);
	}
	return 0;
}