Submission #779945

#	Time	Username	Problem	Language	Result	Execution time	Memory
779945		vjudge1	Palindrome-Free Numbers (BOI13_numbers)	C++17	100 / 100	1 ms	340 KiB

numbers

//#pragma GCC optimize("conserve-stack,no-stack-protector")
#pragma GCC optimize("O3,unroll-loops")
//#pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma,tune=native")
#include<bits/stdc++.h>
#define pii pair<int, int>
#define fi first
#define se second
#define pb push_back
#define int long long
//#define mod 998244353
using namespace std;
using ll=long long;
const int MN=1025;
int dp[20][11][11][2][2];
string t;
//const int inf = 1e18;
int DP(int pos, int lst1, int lst2, bool eq, bool start) {
	if(pos==t.size()) return 1;
	if(dp[pos][lst1+1][lst2+1][eq][start]!=-1) return dp[pos][lst1+1][lst2+1][eq][start];
	int ans=0;
	if(!start) {
		ans+=DP(pos+1,-1,-1,false,false);
		if(eq) {
			int limit=t[pos]-'0';
			for (int i=1; i<=limit; i++) {
				ans+=DP(pos+1,i,-1,(i==limit),true);
			}
		}
		else {
			for (int i=1; i<=9; i++) {
				ans+=DP(pos+1,i,-1,false,true);
			}
		}
	}
	else {
		if(eq) {
			int limit=t[pos]-'0';
			for (int i=0; i<=limit; i++) {
				if(i==lst1||i==lst2) continue;
				ans+=DP(pos+1,i,lst1,(i==limit), true);
			}
		}
		else {
			for (int i=0; i<=9; i++) {
				if(i==lst1||i==lst2) continue;
				ans+=DP(pos+1,i,lst1,false,true);
			}
		}
	}
	return dp[pos][lst1+1][lst2+1][eq][start]=ans;
}
int dp_digit(int x) {
	if(x<0) return 0;
	t=to_string(x);
	memset(dp,-1,sizeof(dp));
	return DP(0,-1,-1,1,0);
}
inline void solve() {
	int l,r;
	cin>>l>>r;
	cout<<dp_digit(r)-dp_digit(l-1);
}
signed main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int t=1;
//	cin>>t;
	while(t--) {
		solve();
	}
}

Compilation message (stderr)

numbers.cpp: In function 'long long int DP(long long int, long long int, long long int, bool, bool)':
numbers.cpp:18:8: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |  if(pos==t.size()) return 1;
      |     ~~~^~~~~~~~~~

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