#/***********************************************************
#    srchmat.rb -- 2次元の探索
#***********************************************************/
NOT_FOUND = false
FOUND = true
def searchmat( x, a, imin, imax, jmin, jmax)
    i = imax;  j = jmin
    while (a[i][j] != x) 
        if (a[i][j] < x); j += 1; else; i -= 1; end
        if (i < imin || j > jmax); return NOT_FOUND; end
    end
    return FOUND, i, j
end

a = [[1, 2, 3, 4], [2, 4, 6, 8], [3, 6, 9, 12]]

print "    1  2  3  4\n",
      "A = 2  4  6  8  (i = 0, 1, 2; j = 0, 1, 2, 3)\n",
      "    3  6  9 12\n",
      "何を探しますか? "
x = gets.to_i
cond, i, j = searchmat(x, a, 0, 2, 0, 3)
if (cond == FOUND)
    printf("(i, j) = (%d, %d)\n", i, j)
else
    printf("見つかりません\n")
end

exit 0