P1355 Mysterious Big Triangle

Determine the positional relationship between a point and a given triangle.

- The first three lines, each contains a coordinate, representing the three vertices of the triangle. - The fourth line contains the coordinate of a point. Determine the positional relationship between this point and the triangle formed by the previous three points. - All coordinate values are integers.

- If the point is inside the triangle (excluding the boundary), output $1$. - If the point is outside the triangle (excluding the boundary), output $2$. - If the point is on the boundary of the triangle (excluding vertices), output $3$. - If the point is on a vertex of the triangle, output $4$.

### Constraints For $100\%$ testdata, $0 \le x_i, y_i \le 100$. Translated by ChatGPT 5