Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over 



[
1
,
…
,
20
]


{\displaystyle [1,\ldots ,20]}

.

The loops iterate rows and columns of the array printing the elements until the value 



20


{\displaystyle 20}

 is met.

Specifically, this task also shows how to break out of nested loops.



Related tasks

   Loop over multiple arrays simultaneously
   Loops/Break
   Loops/Continue
   Loops/Do-while
   Loops/Downward for
   Loops/For
   Loops/For with a specified step
   Loops/Foreach
   Loops/Increment loop index within loop body
   Loops/Infinite
   Loops/N plus one half
   Loops/Nested
   Loops/While
   Loops/with multiple ranges
   Loops/Wrong ranges


# You can't break an outer loop unless you return from the whole function.
n := 40;
a := List([1 .. n], i -> List([1 .. n], j -> Random(1, 20)));;
 
Find := function(a, x)
    local i, j, n;
    n := Length(a);
    for i in [1 .. n] do
        for j in [1 .. n] do
            if a[i][j] = x then
                return [i, j];
            fi;
        od;
    od;
    return fail;
end;
 
Find(a, 20);