CodeForces 675 A Infinite Sequence

F - Infinite Sequence

Time Limit:1000MS     Memory Limit:262144KB     64bit IO Format:%I64d & %I64u

Submit Status

Description

Vasya likes everything infinite. Now he is studying the properties of a sequence s, such that its first element is equal to a (s₁ = a), and the difference between any two neighbouring elements is equal to c (s_i - s_i - 1 = c). In particular, Vasya wonders if his favourite integerb appears in this sequence, that is, there exists a positive integer i, such that s_i = b. Of course, you are the person he asks for a help.

Input

The first line of the input contain three integers a, b and c ( - 10⁹ ≤ a, b, c ≤ 10⁹) — the first element of the sequence, Vasya's favorite number and the difference between any two neighbouring elements of the sequence, respectively.

Output

If b appears in the sequence s print "YES" (without quotes), otherwise print "NO" (without quotes).

Sample Input

Input

1 7 3

Output

YES

Input

10 10 0

Output

YES

Input

1 -4 5

Output

NO

Input

0 60 50

Output

NO

题意：给出等差数列的首项a，相邻两项的差c，问b是否在该数列中，

思路：数学题，分情况讨论一下。

#include<stdio.h>#include<string.h>#include<algorithm>using namespace std;int main(){int a,b,c,i,j,k,sum;scanf("%d%d%d",&a,&b,&c);if(c==0){if(a==b)printf("YES\n");elseprintf("NO\n");}else  if(c>0){if(b<a)printf("NO\n");else if((b-a)%c==0)printf("YES\n");elseprintf("NO\n");}else{c=-c;if(b>a)printf("NO\n");else if((a-b)%c==0)printf("YES\n");elseprintf("NO\n"); }return 0;}