标准数独基础上，提示数字表示从这一方向上观察，大数字能遮住小数字时，可以看见的数字的个数。
Classic rules applied. Additionally, clue shows how many numbers can be seen in this direction, when larger number will hide lower ones.
标准数独基础上，每条线条上的数字之和等于圆圈里的数字。
Classic rules applied. Additionally, the sum of numbers on each line is the numbers in circle.
标准数独基础上，提示表示这一方向上有多少种数字。
Classic rules applied. Additionally, clue shows how many kinds of number on it's direction.
标准数独基础上，提示是其周围数字的和。
Classic rules applied. Additionally, numbers in circle is the sum of the numbers around it.
标准数独基础上，提示A的周围数字中，任意两个数字的和不是A。
Classic rules applied. Additionally, each two numbers around clue A, their sum cannot be A.
标准数独基础上，每一条线条上的数字都有着相同的奇偶性。
Classic rules applied. Additionally, numbers in each zone have same parity.
填入1~9，使得每行、列、宫，以及每一组由灰色线条连结的单元格内的数字不重复。提示表示沿该方向（如在角落，则表示斜向）观察，可以看见的摩天楼数，并且视线会沿着灰色线条拐弯。Write 1~9, make numbers no repeated in each Row, Column, Box, and each group cells combined by grey lines. The clue is the Skyscraper numbers on this direction (slant direction when the clue is on the corner), with seesights turn with the grey lines.
标准数独基础上，提示数周围四个数字中，有一个数字是其余三个数字的和。符合条件的情况被全部标记。Classic rules applied. Additionally, around each black dot, one of the numbers is the sum of other three numbers. All cases fit this rule are all marked.
标准数独基础上，箭头格为N，箭头指向N+1。
Classic rules applied. Additionally, number N in arrow cell, N+1 in the direction the arrow points.
标准数独基础上，每个区域内的多位数是平方数（从左到右，上到下观察）。
Classic rules applied. Additionally, numbers in colored zones should be square numbers with order (left→right, up→down).
