Number Line Jumps

You are choreographing a circus show with various animals. For one act, you are given two kangaroos on a number line ready to jump in the positive direction (i.e, toward positive infinity).

The first kangaroo starts at location and moves at a rate of meters per jump.
The second kangaroo starts at location and moves at a rate of meters per jump.

You have to figure out a way to get both kangaroos at the same location at the same time as part of the show. If it is possible, return YES, otherwise return NO.

Example

After one jump, they are both at , (, ), so the answer is YES.

Function Description

Complete the function kangaroo in the editor below.

kangaroo has the following parameter(s):

int x1, int v1: starting position and jump distance for kangaroo 1
int x2, int v2: starting position and jump distance for kangaroo 2

Returns

string: either YES or NO

Input Format

A single line of four space-separated integers denoting the respective values of , , , and .

Constraints

Sample Input 0

0 3 4 2

Sample Output 0

YES

Explanation 0

The two kangaroos jump through the following sequence of locations:

From the image, it is clear that the kangaroos meet at the same location (number on the number line) after same number of jumps ( jumps), and we print YES.

Sample Input 1

0 2 5 3

Sample Output 1

NO

Solution

#include <bits/stdc++.h>

using namespace std;

string ltrim(const string &);
string rtrim(const string &);
vector<string> split(const string &);

/*
* Complete the 'kangaroo' function below.
*
* The function is expected to return a STRING.
* The function accepts following parameters:
* 1. INTEGER x1
* 2. INTEGER v1
* 3. INTEGER x2
* 4. INTEGER v2
*/

string kangaroo(int x1, int v1, int x2, int v2) {
double res = (double)(x1 - x2) / (v2 - v1);
// Check if res isn't an INF value (if v2 - v1 = 0)
if (res == floor(res) && res >= 0 && !isinf(res))
return string("YES");

return string("NO");
}

int main()
{
ofstream fout(getenv("OUTPUT_PATH"));

string first_multiple_input_temp;
getline(cin, first_multiple_input_temp);

vector<string> first_multiple_input = split(rtrim(first_multiple_input_temp));

int x1 = stoi(first_multiple_input[0]);

int v1 = stoi(first_multiple_input[1]);

int x2 = stoi(first_multiple_input[2]);

int v2 = stoi(first_multiple_input[3]);

string result = kangaroo(x1, v1, x2, v2);

fout << result << "\n";

fout.close();

return 0;
}

string ltrim(const string &str) {
string s(str);

s.erase(
s.begin(),
find_if(s.begin(), s.end(), not1(ptr_fun<int, int>(isspace)))
);

return s;
}

string rtrim(const string &str) {
string s(str);

s.erase(
find_if(s.rbegin(), s.rend(), not1(ptr_fun<int, int>(isspace))).base(),
s.end()
);

return s;
}

vector<string> split(const string &str) {
vector<string> tokens;

string::size_type start = 0;
string::size_type end = 0;

while ((end = str.find(" ", start)) != string::npos) {
tokens.push_back(str.substr(start, end - start));

start = end + 1;
}

tokens.push_back(str.substr(start));

return tokens;
}

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