Square Route (hard)
This maze first appeared as the monthly maze competition for July 2012.
Start on the 0 in the top left corner. Move horizontally or vertically to any number in the same row or column and add that to your total. Continue in this way, making a series of horizontal or vertical jumps, each time adding the number you reach to your total. The restriction is that at each jump the total must be a perfect square.
For example, from the 0 on the starting square you could move right to the 9, making 9, and down to the 7, making 16, and back up to the 9, making 25. However, now you're stuck.
The aim is to find the shortest route to the 21 in the bottom right corner.
To solve this maze you'll need to use a pencil and paper; you can't solve it interactively.
Solution
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Show solution.