Description
Initially, there is a Robot at position (0, 0). Given a sequence of its moves, judge if this robot makes a circle, which means it moves back to the original place.
The move sequence is represented by a string. And each move is represent by a character. The valid robot moves are R (Right), L (Left), U (Up) and D (down). The output should be true or false representing whether the robot makes a circle.
Example 1:
Input: "UD"
Output: true
Example 2:
Input: "LL"
Output: false
Solution
简单题。
class Solution {
public boolean judgeCircle(String moves) {
int xOffset = 0;
int yOffset = 0;
for (int i = 0; i < moves.length(); ++i) {
switch(moves.charAt(i)) {
case 'R':
++xOffset;
continue;
case 'L':
--xOffset;
continue;
case 'U':
++yOffset;
continue;
case 'D':
--yOffset;
continue;
default:
continue;
}
}
return xOffset == 0 && yOffset == 0;
}
}
