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Robot Trouble

Five students at five different colleges were working on their five robots for the Collegiate Robot Invitational the upcoming weekend. On each day in the week before the competition, one student found both a hardware bug and a software bug in their robot.

For each day (Monday to Friday), determine the name of the robot that had problems, the physical problem, the software problem, and the school where the robot broke down.

1. The Dartmouth student discovered his bugs later in the week than the student who broke a gear, and earlier than the one who got the Out of memory exception.

2. The student who built the R2-D2 robot discovered his bugs before the student from Rose-Hulman, who found his before the student whose motor burned out.

3. The kid from Cornell found his bugs later than the kid who had the stack overflow, and earlier than the student who built Bender the Robot.

4. The broken gear (which was not one of R2-D2’s problems) did not happen to the same robot that had the Stack overflow error.

5. The Cornell student did not have an infinite loop in his code. The Infinite loop error was found the day before one of the other robots’ bearings rusted out.

6. The robot at Rose-Hulman did not have any gear-related issues, nor any stack overflows.

7. Robby the Robot (who did not have an Out of memory exception) broke on the day after WALL•E broke.

8. Bender the Robot (who wasn’t at Stanford) didn’t have any timing belt issues.

9. The robot that had the Off by 1 error did not have a bent spring.

10. The burned-out motor was not a problem at Stanford or MIT, and the MIT kid did not have an Out of memory exception.

11. R2-D2 wasn’t at Stanford or MIT.

12. One of the robots was named Roomba. One of the robots had a Divide by 0 error.


Software errors are:
Out of memory
Off by 1
Divide by 0
Stack overflow
Infinite loop

Hardware problems are:
Gear problems
Rusted bearings
Timing belt issues
Burned-out motor
Bent spring

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Michael H. Pryor

Michael H. Pryor is the co-founder and president of Fog Creek Software. He runs a technical interview site at techinterview.org

View more articles by Michael H. Pryor


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