Submission #976887

#	Time	Username	Problem	Language	Result	Execution time	Memory
976887		LOLOLO	Palindrome-Free Numbers (BOI13_numbers)	C++14	100 / 100	2 ms	600 KiB

numbers

#include <bits/stdc++.h>
#define ll long long
using namespace std;
 
#define           f     first
#define           s     second
#define           pb    push_back
#define           ep    emplace
#define           eb    emplace_back
#define           lb    lower_bound
#define           ub    upper_bound
#define       all(x)    x.begin(), x.end()
#define      rall(x)    x.rbegin(), x.rend()
#define   uniquev(v)    sort(all(v)), (v).resize(unique(all(v)) - (v).begin())
#define     mem(f,x)    memset(f , x , sizeof(f))
#define        sz(x)    (int)(x).size()
#define  __lcm(a, b)    (1ll * ((a) / __gcd((a), (b))) * (b))
#define          mxx    *max_element
#define          mnn    *min_element
#define    cntbit(x)    __builtin_popcountll(x)
#define       len(x)    (int)(x.length())
 
const int N = 2e5 + 100;
ll f[20][11][11][2][2];

string s;
ll dq(int id, int a, int b, int is, int mean) {
    if (id == len(s))
        return 1;

    if (f[id][a][b][is][mean] != -1)
        return f[id][a][b][is][mean];

    ll ans = 0;
    int lim = is ? 9 : s[id] - '0';
    if (mean == 0) {
        for (int i = 0; i <= lim; i++) {
            if (i == 0) {
                ans += dq(id + 1, a, b, 1, 0);
            } else {
                ans += dq(id + 1, b, i, is | (i < (s[id] - '0')), 1);
            }
        }
    } else {
        for (int i = 0; i <= lim; i++) {
            if (i != a && i != b) {
                ans += dq(id + 1, b, i, is | (i < (s[id] - '0')), 1);
            }
        }
    }

    return f[id][a][b][is][mean] = ans;
}

ll cal(ll a) {
    s = to_string(a);
    mem(f, -1);
    return dq(0, 10, 10, 0, 0); 
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    ll a, b;
    cin >> a >> b;
    cout << cal(b) - cal(a - 1) << '\n';

    return 0;
}

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