Submission #68098

#	Time	Username	Problem	Language	Result	Execution time	Memory
68098		thebes	Palindrome-Free Numbers (BOI13_numbers)	C++14	100 / 100	4 ms	1144 KiB

numbers

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
ll dp[20][11][11][2], N, a, b;
string s;
ll solve(ll n,ll a,ll b,ll m){
	if(n==s.size()) return 1;
	else if(dp[n][a][b][m]!=-1) return dp[n][a][b][m];
	else{
		dp[n][a][b][m] = 0;
		ll &val = dp[n][a][b][m];
		for(int i=0;i<=(m?s[n]-'0':9);i++){
			if(i==a||i==b) continue;
			if(i==0&&b==10&&a==10) val+=solve(n+1,a,b,0);
			else val+=solve(n+1,i,a,m&&i==s[n]-'0');
		}
		return dp[n][a][b][m];
	}
}
ll solve(){
	memset(dp, -1, sizeof(dp));
	return solve(0,10,10,1);
}
int main(){
	cin >> N; s=to_string(N-1);
	if(N-1==-1) a = 0;
	else a = solve(); 
	cin >> N; s=to_string(N);
	b = solve();
	printf("%lld\n",b-a);
	return 0;
}

Compilation message (stderr)

numbers.cpp: In function 'll solve(ll, ll, ll, ll)':
numbers.cpp:8:6: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if(n==s.size()) return 1;
     ~^~~~~~~~~~

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