HDU 5062 Beautiful Palindrome Number（暴力）

HDU 5062 Beautiful Palindrome Number

题目链接

才6种答案，直接暴力或者手算都可以

代码：

#include <cstdio>
#include <cstring>
#include <set>
#include <algorithm>
#include <vector>
using namespace std;

int t, n;

int dfs(int u, int pre) {
	if (u == n) return 1;
	int ans = 0;
	for (int i = pre + 1; i <= 9; i++)
		ans += dfs(u + 1, i);
	return ans;
}

int ans[10];

int main() {
	scanf("%d", &t);
	ans[0] = 1;
	ans[1] = 9;
	for (int i = 2; i <= 6; i++) {
		n = (i + 1) / 2;
		ans[i] = ans[i - 1] + dfs(0, 0);
	}
	while (t--) {
		scanf("%d", &n);
		printf("%d\n", ans[n]);
	}
	return 0;
}