Codeforces597A

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

今天这道题算是一道水题,但是却给了我对取余的新认识,也促使我对乘除法的形象化认识,除法就是在一个单位内找到有多少个另一个单位个数,做这种图只需要把题意形象化就可以了

此题分一下类就OK还有一点我觉得比较好的想法就是对1的处理本题用了-(a-1)/c==-(a/c)+1/c;只有当1时1/C才会起作用;

#include<iostream>
#include<stdio.h>
using namespace std;

int main()
{
    long long a,b,c;
    cin>>c>>a>>b;
    long long ans = 0;
    if(a<=0&&b<=0)
    {
        swap(a,b);
        a = -a,b = -b;
    }
    if(a<=0&&b>=0)
    {
        ans = (-a)/c+b/c;
        ans ++;
    }
    else
    {
        ans = (b/c)-(a-1)/c;
    }
    cout<<ans<<endl;
}
原文地址:https://www.cnblogs.com/VectorLin/p/5147614.html