Check if it is possible to reach (x, y) from origin in exactly Z steps using only plus movements

Given a point (x, y), the task is to check if it is possible to reach from origin to (x, y) in exactly Z steps. From a given point (x, y) we can only moves in four direction left(x - 1, y), right(x + 1, y), up(x, y + 1) and down(x, y - 1).
Examples: 
 

Input: x = 5, y = 5, z = 11 
Output: Not Possible
Input: x = 10, y = 15, z = 25 
Output: Possible 
 

Approach: 
 

1. The shortest path from origin to (x, y), is |x|+|y|.
2. So, it is clear that if Z less than |x|+|y|, then we can't reach (x, y) from origin in exactly Z steps.
3. If the number of steps is not less than |x|+|y| then, we have to check below two conditions to check if we can reach to (x, y) or not: 
   
   • If Z ? |x| + |y|, and
   • If (Z - |x| + |y|)%2 is 0.
4. For the second conditions in the above step, if we reach (x, y), we can take two more steps such as (x, y)-->(x, y+1)-->(x, y) to come back to the same position (x, y). And this is possible only if difference between them is even.

Below is the implementation of the above approach:
 

// C++ program for the above approach
#include <bits/stdc++.h> 
using namespace std;

// Function to check if it is possible to
// reach (x, y) from origin in exactly z steps
void possibleToReach(int x, int y, int z)
{

    // Condition if we can't reach in Z steps
    if (z < abs(x) + abs(y)
        || (z - abs(x) - abs(y)) % 2) {
        cout << "Not Possible" << endl;
    }
    else
        cout << "Possible" << endl;
}

// Driver Code
int main()
{
    // Destination point coordinate
    int x = 5, y = 5;

    // Number of steps allowed
    int z = 11;

    // Function Call
    possibleToReach(x, y, z);
    return 0;
}

// Java program for the above approach
class GFG{

// Function to check if it is possible 
// to reach (x, y) from origin in 
// exactly z steps
static void possibleToReach(int x, int y, int z)
{
    
    // Condition if we can't reach in Z steps
    if (z < Math.abs(x) + Math.abs(y) ||
       (z - Math.abs(x) - Math.abs(y)) % 2 == 1) 
    {
        System.out.print("Not Possible" + "\n");
    }
    else
        System.out.print("Possible" + "\n");
}

// Driver Code
public static void main(String[] args)
{
    
    // Destination point coordinate
    int x = 5, y = 5;

    // Number of steps allowed
    int z = 11;

    // Function Call
    possibleToReach(x, y, z);
}
}

// This code is contributed by 29AjayKumar

# Python3 program for the above approach

# Function to check if it is possible to
# reach (x, y) from origin in exactly z steps
def possibleToReach(x, y, z):

    #Condition if we can't reach in Z steps
    if (z < abs(x) + abs(y) or 
       (z - abs(x) - abs(y)) % 2):
        print("Not Possible")
    else:
        print("Possible")

# Driver Code
if __name__ == '__main__':
    
    # Destination point coordinate
    x = 5
    y = 5

    # Number of steps allowed
    z = 11

    # Function call
    possibleToReach(x, y, z)

# This code is contributed by mohit kumar 29

// C# program for the above approach
using System;
class GFG{

// Function to check if it is possible 
// to reach (x, y) from origin in 
// exactly z steps
static void possibleToReach(int x, int y, int z)
{
    
    // Condition if we can't reach in Z steps
    if (z < Math.Abs(x) + Math.Abs(y) ||
       (z - Math.Abs(x) - Math.Abs(y)) % 2 == 1) 
    {
        Console.Write("Not Possible" + "\n");
    }
    else
        Console.Write("Possible" + "\n");
}

// Driver Code
public static void Main(String[] args)
{
    
    // Destination point coordinate
    int x = 5, y = 5;

    // Number of steps allowed
    int z = 11;

    // Function Call
    possibleToReach(x, y, z);
}
}

// This code is contributed by 29AjayKumar

<script>
// javascript program for the above approach


// Function to check if it is possible 
// to reach (x, y) from origin in 
// exactly z steps
function possibleToReach(x , y , z)
{
    
    // Condition if we can't reach in Z steps
    if (z < Math.abs(x) + Math.abs(y) ||
       (z - Math.abs(x) - Math.abs(y)) % 2 == 1) 
    {
        document.write("Not Possible" + "\n");
    }
    else
        document.write("Possible" + "\n");
}

// Driver Code 
// Destination point coordinate
var x = 5, y = 5;

// Number of steps allowed
var z = 11;

// Function Call
possibleToReach(x, y, z);

// This code is contributed by Amit Katiyar 
</script>

Not Possible

Time Complexity: O(1) 
Auxiliary Space: O(1)