[題解]Leetcode 335 Self Crossing

335 Self Crossing

題目連結

class Solution {
public:
    bool isSelfCrossing(vector<int>& d) {
        int n = d.size();
        if(n <= 3)return false;
        for(int i = 3;i < n;i++){
            //第四條、第五條、第六條交第一條
            if(d[i] >= d[i-2] && d[i-1] <= d[i-3])return true;
            if(i >= 4 && d[i-1] == d[i-3] && d[i] + d[i-4] >= d[i-2])return true;
            if(i >= 5 && d[i-2] >= d[i-4] && d[i] >= d[i-2] - d[i-4]
              && d[i-1] >= d[i-3]-d[i-5] && d[i-1] <= d[i-3])return true;
            
        }
        return false;
    }
};