Submission #469675

#	Time	Username	Problem	Language	Result	Execution time	Memory
469675		ZergTricky	Palindrome-Free Numbers (BOI13_numbers)	C++17	100 / 100	1 ms	548 KiB

numbers

#include <bits/stdc++.h>

using namespace std;

#define flush cout.flush

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pl = pair<ll, ll>;
const ll INF = 1e9 + 7;
const ll mod = 1e9 + 7;
const ll mod2 = 998244353;
const ld eps = 1e-9;
const ld PI = acos(-1);
// 576

ll dp[21][11][11][2][2][2];

string a, b;

ll go(ll pos, ll last, ll lastLast, ll f1, ll f2, ll ok) {
    ll &res = dp[pos][last][lastLast][f1][f2][ok];
    if (res != -1) {
        return res;
    }
    if (pos == a.size()) {
        return res = 1;
    }
    res = 0;
    ll x = a[pos] - '0';
    ll y = b[pos] - '0';
    for (ll i = (f1 ? x : 0); i <= (f2 ? y : 9); ++i) {
        if (i == last || i == lastLast && ok)continue;
        res += go(pos + 1, (ok || i != 0 ? i : 10), last, f1 && (i == x), f2 && (i == y), ok || (i != 0));
    }
    return res;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    memset(dp, -1, sizeof(dp));
    ll x, y;
    cin >> x >> y;
    a = to_string(x), b = to_string(y);
    while (a.size() < b.size()) {
        a = '0' + a;
    }
    cout << go(0, 10, 10, 1, 1, 0) << "\n";
    return 0;
}

Compilation message (stderr)

numbers.cpp: In function 'll go(ll, ll, ll, ll, ll, ll)':
numbers.cpp:27:13: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |     if (pos == a.size()) {
      |         ~~~~^~~~~~~~~~~
numbers.cpp:34:40: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   34 |         if (i == last || i == lastLast && ok)continue;
      |                          ~~~~~~~~~~~~~~^~~~~

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