LeetCode: Judge Route Circle

LeetCode: Judge Route Circle

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:

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Input: "UD"
Output: true

Example 2:

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Input: "LL"
Output: false
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class Solution {
public boolean judgeCircle(String moves) {
if (moves == null || moves.isEmpty()) {
return false;
}

int[] start = {0, 0};
for (char c : moves.toCharArray()) {
switch (c) {
case 'R':
start[1]++;
break;
case 'L':
start[1]--;
break;
case 'U':
start[0]--;
break;
case 'D':
start[0]++;
break;
default:
}

}
return start[0] == 0 && start[1] == 0;
}
}