leetcode 1037. 有效的回旋镖(Valid Boomerang)
题目描述:
回旋镖定义为一组三个点,这些点各不相同且不在一条直线上。
给出平面上三个点组成的列表,判断这些点是否可以构成回旋镖。
示例 1:
输入:[[1,1],[2,3],[3,2]]
输出:true
示例 2:
输入:[[1,1],[2,2],[3,3]]
输出:false
提示:
points.length == 3
points[i].length == 2
0 <= points[i][j] <= 100
解法:
class Solution {
public:
bool isSamePoint(vector<int>& pt1, vector<int>& pt2){
return pt1[0] == pt2[0] && pt1[1] == pt2[1];
}
bool isBoomerang(vector<vector<int>>& points) {
if(isSamePoint(points[0], points[1])
|| isSamePoint(points[0], points[2])
|| isSamePoint(points[1], points[2])){
return false;
}else{
int x1 = points[0][0] - points[1][0];
int y1 = points[0][1] - points[1][1];
int x2 = points[0][0] - points[2][0];
int y2 = points[0][1] - points[2][1];
return x1*y2 != x2*y1;
//(1, 1), (2, 2)
}
}
};