Submission #1124074

#	Time	Username	Problem	Language	Result	Execution time	Memory
1124074		kustizus	Palindrome-Free Numbers (BOI13_numbers)	C++20	100 / 100	1 ms	328 KiB

numbers

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

#define int long long
#define fi first
#define se second
#define sz(s) (int)s.size()
#define bit(i, j) ((j >> i) & 1)
#define all(v) v.begin(), v.end()
#define taskname "file"

typedef long long ll;

int a, b, dp[19][11][11][2][2];
vector <int> v;

void cs(int x){
    while (x){
        v.push_back(x % 10);
        x /= 10;
    }
    reverse(all(v));
}

int get(int x){
    if (x <= 9) return 0;
    v.clear();
    cs(x);
    for (int cs = 1; cs <= sz(v); ++cs)
        for (int i = 0; i <= 10; ++i)
            for (int j = 0; j <= 10; ++j)
                for (int k = 0; k < 2; ++k)
                    for (int l = 0; l < 2; ++l)
                        dp[cs][i][j][k][l] = 0;
    for (int i = 0; i < 10; ++i)
        if (i <= v[0]) dp[1][(!i ? 10 : i)][10][i == v[0]][0] = 1;
        else break;
    for (int cs = 1; cs < sz(v); ++cs)
        for (int i = 0; i <= 10; ++i)
            for (int j = 0; j <= 10; ++j)
                for (int k = 0; k < 2; ++k)
                    for (int l = 0; l < 2; ++l){
                        if (!dp[cs][i][j][k][l]) continue;
                        for (int nxt = 0; nxt <= (k ? v[cs] : 9); ++nxt){
                            if (i == 10 && !nxt) dp[cs + 1][10][10][0][0] = 1;
                            else{
                                int l1 = l | (nxt == i) | (cs > 1 && nxt == j);
                                dp[cs + 1][nxt][i][k & (nxt == v[cs])][l1] += dp[cs][i][j][k][l];
                            }
                        }
                    }
    int ans = 0;
    for (int i = 0; i < 10; ++i)
        for (int j = 0; j < 10; ++j)
            for (int k = 0; k < 2; ++k)
                ans += dp[sz(v)][i][j][k][1];
    return ans;
}

void solve(){
    cin >> a >> b;
    cout << b - a + 1 - get(b) + get(a - 1);
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    // freopen(taskname".inp", "r", stdin);
    // freopen(taskname".out", "w", stdout);
    int tt = 1;
    // cin >> tt;
    while (tt--) solve();
}

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