Submission #520895

#	Time	Username	Problem	Language	Result	Execution time	Memory
520895		SmolBrain	Palindrome-Free Numbers (BOI13_numbers)	C++17	100 / 100	1 ms	488 KiB

numbers

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long int ll;
typedef long double ld;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define endl '\n'
#define pb push_back
#define conts continue
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
#define ff first
#define ss second
#define ceil2(x,y) ((x+y-1) / (y))
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#ifndef ONLINE_JUDGE
#define debug(x) cout << #x <<" = "; print(x); cout << endl
#else
#define debug(x)
#endif

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define trav(i,a) for(auto &i : a)

bool iseven(ll n) {if ((n & 1) == 0) return true; return false;}

void print(ll t) {cout << t;}
void print(int t) {cout << t;}
void print(string t) {cout << t;}
void print(char t) {cout << t;}
void print(double t) {cout << t;}
void print(ld t) {cout << t;}

template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(pair <T, V> p) {cout << "{"; print(p.ff); cout << ","; print(p.ss); cout << "}";}
template <class T> void print(vector <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(set <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(multiset <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T, class V> void print(map <T, V> v) {cout << "[ "; for (auto i : v) {print(i); cout << " ";} cout << "]";}

void usaco(string filename) {
    freopen((filename + ".in").c_str(), "r", stdin);
    freopen((filename + ".out").c_str(), "w", stdout);
}

const int MOD = 1e9 + 7;
const int maxn = 1e5 + 5;
const int inf1 = 1e9 + 5;
const ll inf2 = ll(1e18) + 5;

ll n;
vector<ll> a(25);
ll dp[25][15][15][2][2];

ll calc(ll i, ll prev1, ll prev2, bool tight, bool nonzero) {
    if(i > n){
        return 1;
    }
    
    if(dp[i][prev1][prev2][tight][nonzero] != -1){
        return dp[i][prev1][prev2][tight][nonzero];
    }

    ll mx = 9;
    if(tight) mx = a[i];

    ll ans = 0;

    rep(j, mx + 1){
        // check for 2 or 3 length palindrome
        if(j == prev1 or j == prev2){
            conts;
        }

        bool tight2 = tight, nonzero2 = nonzero;
        if(j < mx) tight2 = 0;
        if(j) nonzero2 = 1;

        if(nonzero2){
            ans += calc(i + 1, j, prev1, tight2, nonzero2);
        }
        else{
            ans += calc(i + 1, prev1, prev2, tight2, nonzero2);
        }
    }

    return dp[i][prev1][prev2][tight][nonzero] = ans;
}

ll get(ll x) {
    string s = to_string(x);
    n = sz(s);
    rep(i, n) a[i + 1] = s[i] - '0';
    memset(dp, -1, sizeof dp);

    ll ans = calc(1, 10, 10, 1, 0);
    return ans;
}

void solve(int test_case)
{
    ll x, y; cin >> x >> y;
    ll ans = get(y) - get(x - 1);
    cout << ans << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;
    rep1(i, t) {
        solve(i);
    }

    return 0;
}

Compilation message (stderr)

numbers.cpp: In function 'void usaco(std::string)':
numbers.cpp:56:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |     freopen((filename + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
numbers.cpp:57:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |     freopen((filename + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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