Submission #77196

#	Time	Username	Problem	Language	Result	Execution time	Memory
77196		DrumpfTheGodEmperor	Palindrome-Free Numbers (BOI13_numbers)	C++14	72.50 / 100	3 ms	740 KiB

numbers

#include <bits/stdc++.h>
#define MOD 1000000007
#define INF 1061109567
#define int long long
#define __builtin_popcount __builtin_popcountll
#define pb push_back
#define in(s) freopen(s,"r",stdin);
#define out(s) freopen(s,"w",stdout);
#define fi first
#define se second
#define bw(i,r,l) for (int i=r-1;i>=l;i--)
#define fw(i,l,r) for (int i=l;i<r;i++)
#define fa(i,x) for (auto i:x)
using namespace std;
int a, b, dig[19], dp[19][11][11];
int solve(int i, int j, int k, bool flag) {
	if (!i) return 1;
	if (dp[i][j][k] != -1 && !flag) return dp[i][j][k];
	int n = (flag ? dig[i] : 9), ans = 0;
	fw (nxt, 0, n + 1) if (nxt != j && nxt != k) {
		ans += solve(i - 1, nxt, j, flag && nxt == n ? 1 : 0);
	}
	if (!flag) dp[i][j][k] = ans;
	return ans;
}
int calc(int r) {
	if (r == -1) return 0;
	int cnt = 0;
	while (r) {
		dig[++cnt] = r % 10;
		r /= 10;
	}
	return solve(cnt, 10, 10, 1);
}
signed main() {
	#ifdef aome
	in("aome.inp");	
	#endif
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin >> a >> b;
	memset(dp, -1, sizeof dp);
	cout << calc(b) - calc(a - 1) << "\n";
	return 0;
}

• Subtask 1: 12.5 / 25
• Subtask 2: 60 / 75