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class Solution {
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 public:
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  bool isRobotBounded(string instructions) {
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    char direction = 'N';
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    int x = 0, y = 0;
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    for (char &instruction : instructions) {
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      if (instruction == 'G') {
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        if (direction == 'N')
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          y++;
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        else if (direction == 'S')
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          y--;
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        else if (direction == 'W')
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          x--;
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        else
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          x++;
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      } else if (instruction == 'L') {
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        if (direction == 'N')
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          direction = 'W';
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        else if (direction == 'S')
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          direction = 'E';
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        else if (direction == 'W')
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          direction = 'S';
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        else
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          direction = 'N';
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      } else {
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        if (direction == 'N')
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          direction = 'E';
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        else if (direction == 'S')
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          direction = 'W';
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        else if (direction == 'W')
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          direction = 'N';
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        else
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          direction = 'S';
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      }
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    }
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    return (x == 0 && y == 0) || direction != 'N';
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  }
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};