Leetcode 657 Robot Return to Origin (C, C++, C#, Java, Javascript, Ruby)

657. Robot Return to Origin

There is a robot starting at position (0, 0), the origin, on a 2D plane. Given a sequence of its moves, judge if this robot ends up at (0, 0) after it completes its moves.

The move sequence is represented by a string, and the character moves[i] represents its ith move. Valid moves are R (right), L (left), U (up), and D (down). If the robot returns to the origin after it finishes all of its moves, return true. Otherwise, return false.

Note: The way that the robot is “facing” is irrelevant. “R” will always make the robot move to the right once, “L” will always make it move left, etc. Also, assume that the magnitude of the robot’s movement is the same for each move.

Example 1:

Input: moves = "UD"
Output: true
Explanation: The robot moves up once, and then down once. All moves have the same magnitude, so it ended up at the origin where it started. Therefore, we return true.

Example 2:

Input: moves = "LL"
Output: false
Explanation: The robot moves left twice. It ends up two "moves" to the left of the origin. We return false because it is not at the origin at the end of its moves.

Example 3:

Input: moves = "RRDD"
Output: false

Example 4:

Input: moves = "LDRRLRUULR"
Output: false

Constraints:

• 1 <= moves.length <= 2 * 104
• moves only contains the characters 'U', 'D', 'L' and 'R'.

//C

bool judgeCircle(char * moves){
    
    int length = strlen(moves);
    
    int x = 0;
    int y = 0;
    int i = 0;
    
    for(i = 0; i < length; i++)
    {
        if(moves[i] == 'R')
            x++;    
        else if(moves[i] == 'L')
            x--;
        else if(moves[i] == 'U')
            y++;    
        else if(moves[i] == 'D')
            y--;
    }
    return (x == 0 && y == 0);
}
//C++
class Solution {
public:
    bool judgeCircle(string moves) {
        int x = 0;
        int y = 0;
        
        for(int i = 0; i < moves.length(); i++)
        {
            if(moves[i] == 'R')
                x++;    
            else if(moves[i] == 'L')
                x--;
            else if(moves[i] == 'U')
                y++;    
            else if(moves[i] == 'D')
                y--;
        }
        return (x == 0 && y == 0);
    }
};
//C#
public class Solution {
    public bool JudgeCircle(string moves) {
        int x = 0;
        int y = 0;
        
        char[] array = moves.ToCharArray();
        
        for(int i = 0; i < array.Length; i++)
        {
            if(array[i] == 'R')
                x++;    
            else if(array[i] == 'L')
                x--;
            else if(array[i] == 'U')
                y++;    
            else if(array[i] == 'D')
                y--;
        }
        return (x == 0 && y == 0);
    }
}
//Java
class Robot
{
    public static void main(String[] args) {
        Solution sl = new Solution();
        System.out.println(sl.judgeCircle("UD"));
    }
}
class Solution {
    public boolean judgeCircle(String moves) {
        int x = 0;
        int y = 0;
        
        char[] array = moves.toCharArray();
        
        for(int i = 0; i < array.length; i++)
        {
            if(array[i] == 'R')
                x++;    
            else if(array[i] == 'L')
                x--;
            else if(array[i] == 'U')
                y++;    
            else if(array[i] == 'D')
                y--;
        }
        return (x == 0 && y == 0);
    }
}
//Javascript
var judgeCircle = function(moves) {
    let x = 0;
    let y = 0;
    
    let array = moves.split('');
    
    for(let i = 0; i < array.length; i++)
    {
       if(array[i] == 'R')
           x++;    
       else if(array[i] == 'L')
           x--;
       else if(array[i] == 'U')
           y++;    
       else if(array[i] == 'D')
           y--;
    }
    return (x == 0 && y == 0);
};

console.log(judgeCircle("UD"));
//Ruby
def judge_circle(moves)
    (moves.count("R") == moves.count("L")) && (moves.count("D") == moves.count("U"))
end

puts judge_circle("UD");