A move consists of taking a point (x, y)
and transforming it to either (x, x+y)
or (x+y, y)
.
Given a starting point (sx, sy)
and a target point (tx, ty)
, return True
if and only if a sequence of moves exists to transform the point (sx, sy)
to (tx, ty)
. Otherwise, return False
.
Examples:
Input: sx = 1, sy = 1, tx = 3, ty = 5
Output: True
Explanation:
One series of moves that transforms the starting point to the target is:
(1, 1) -> (1, 2)
(1, 2) -> (3, 2)
(3, 2) -> (3, 5) Input: sx = 1, sy = 1, tx = 2, ty = 2
Output: False Input: sx = 1, sy = 1, tx = 1, ty = 1
Output: True 分析:因为对于起始点来讲,它后面的x和y值永远是增加的,所以,如果sx > tx 或者 sy > ty,那么明显是不行的。
但是从小到大找好像不好找,可以换种思维,从大往小找。
class Solution {
public boolean reachingPoints(int sx, int sy, int tx, int ty) {
if (ty < sy || tx < sx) return false;
while (tx >= sx && ty >= sy) {
if (tx > ty) tx %= ty;
else ty %= tx;
}
if (tx == sx) {
return (ty - sy) % sx == ;
}
if (ty == sy) {
return (tx - sx) % sy == ;
}
return false;
}
}