洛谷P1149

[洛谷P1149]([P1149 NOIP2008 提高组] 火柴棒等式 - 洛谷 | 计算机科学教育新生态 (luogu.com.cn))

public class P1149 {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		search(scanner.nextInt());
	}

	public static void search(int n) {// 先写框架后补函数
		int sum = 0;
		for (int a = 0; a <= 720; a++) {
			for (int b = 0; b <= 720; b++) {
				if (f(a) + f(b) + f(a + b) == n - 4) {
					sum++;
				}
			}
		}
		System.out.println(sum);
	}

	public static int f(int n) {
		if (n == 0) {
			return 6;
		}
		int sum = 0;
		int[] a = { 6, 2, 5, 5, 4, 5, 6, 3, 7, 6 };
		while (n != 0) {// 数位拆分
			sum += a[n % 10];
			n /= 10;
		}
		return sum;
	}
}