# KANGAROO hackerrank Solution - Correct, Optimal and Working

``````/*
*  Author: Arpit Bhayani
*  https://arpitbhayani.me
*/
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <climits>
#include <deque>
#include <iostream>
#include <list>
#include <limits>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>

#define ll long long

#define MIN(a, b) a < b ? a : b
#define MAX(a, b) a > b ? a : b

using namespace std;

int i = 0;
char ch;
while((ch = getchar()) != '\n') {
str[i++] = ch;
}
str[i] = '\0';
return i;
}

int main(int argc, char *argv[]) {

int x1, v1, x2, v2;
scanf("%d%d%d%d", &x1, &v1, &x2, &v2);

if(x1 > x2) {
// Ensuring x1 is always behind x1
int t = x1;
x1 = x2;
x2 = t;

t = v1;
v1 = v2;
v2 = t;
}

if(x1 == x2 && v1 == v2) {
printf("YES\n");
}
else if(x1 == x2 && v1 > v2) {
printf("NO\n");
}
else if(x1 <= x2 && v1 <= v2) {
printf("NO\n");
}
else {
if( (x2 - x1) % (v1 - v2) == 0 ) {
printf("YES\n");
}
else {
printf("NO\n");
}
}

return 0;
}
``````