CCF 2020-06-1 線性分類器

菜歸菜，題還是要做的，準備一下9月份的認證考試

題目連結: 2020-06-1 線性分類器.

code

#include<iostream>

using namespace std;


int main() {
	int n, m;
	cin >> n;
	cin >> m;
	
	int (*points)[2] = new int[n][2];
	char *points_flag = new char[n];
	int (*lines)[3] = new int[m][3];
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < 2; j++) {
			cin >> points[i][j];
		}
		cin >> points_flag[i];
	}
	for (int i = 0; i < m; i++) 
		for (int j = 0; j < 3; j++) {
			cin >> lines[i][j];
		}

	char upch;
	string* answer = new string[m];
	for (int i = 0; i < m; i++) {
		if (lines[i][0] + points[0][0] * lines[i][1] + points[0][1] * lines[i][2] > 0) {
			if (points_flag[0] == 'A') {
				upch = 'A';
			}
			else {
				upch = 'B';
			}
		}
		else {
			if (points_flag[0] == 'A') {
				upch = 'B';
			}
			else {
				upch = 'A';
			}
		}   //已擷取目前直線之上的點的标記upch
		int j;
		for (j = 1; j < n; j++) {
			if (lines[i][0] + points[j][0] * lines[i][1] + points[j][1] * lines[i][2] > 0) {
				if (points_flag[j] != upch) {
					answer[i] = "No";
					break;
				}
			}
			else {
				if (points_flag[j] == upch) {
					answer[i] = "No";
					break;
				}
			}
		}
		if (j == n) {
			answer[i] = "Yes";
		}
	}

	for (int i = 0; i < m; i++)
		cout << answer[i] << endl;
	return 0;
}