CCF 201803-4

CCF 201803-4

考虑到题中说明，AB均采用最优策略，通过最大最小搜索完成。

#include<iostream>
using namespace std;
int pad[9];
#define max(a,b) ((a)>(b)?(a):(b))
#define min(a,b) ((a)<(b)?(a):(b))
int status() {
	for (int i = 0; i<3; i++) {
		if (pad[i * 3] != 0 && pad[i * 3] == pad[i * 3 + 1] && pad[i*3] == pad[i * 3 + 2]) {
			return pad[i * 3];
		}
		if (pad[i] != 0 && pad[i] == pad[i + 3] && pad[i] == pad[i + 6]) {
			return pad[i];
		}
	}
	if (pad[4] != 0 && pad[0] == pad[4] && pad[4] == pad[8]) {
		return pad[4];
	}
	if (pad[4] != 0 && pad[2] == pad[4] && pad[4] == pad[6]) {
		return pad[4];
	}
	return 0;
}
int minmax(int depth) {
	if (depth >9) {
		return 0;
	}
	int a = status();//current
	if (a != 0) {
		return (9 - depth + 1)*(a == 1 ? 1 : -1);
	}
	if (depth == 9) {
		return 0;
	}
	if (depth % 2 == 0) {//a.Going to choose the maxScore;
		int maxScore = -10;
		for (int i = 0; i<9; i++) {
			if (pad[i] == 0) {
				pad[i] = 1;
				maxScore = max(maxScore, minmax(depth + 1));
				pad[i] = 0;
			}
		}
		return maxScore;
	}
	else {//B . Going to get min;
		int minScore = 10;
		for (int i = 0; i<9; i++) {
			if (pad[i] == 0) {
				pad[i] = 2;
				minScore = min(minScore, minmax(depth + 1));
				pad[i] = 0;
			}
		}
		return minScore;
	}
}
int main() {
	int T;
	cin >> T;
	int depth = 0;
	while (T-->0) {
		depth = 0;
		for (int i = 0; i<9; i++) {
			cin >> pad[i];
			if (pad[i]) {
				depth++;
			}
		}
		if (depth == 0) {
			cout << 0 << endl;
		}
		else
		{
			cout << minmax(depth) << endl;
		}
	}
	return 0;
}