Submission #1113094

#	Time	Username	Problem	Language	Result	Execution time	Memory
1113094		ljtunas	Palindrome-Free Numbers (BOI13_numbers)	C++14	100 / 100	2 ms	820 KiB

numbers

// author : anhtun_hi , nqg
#include <bits/stdc++.h>
#define ll long long
#define ii pair<ll, ll>
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define reset(h, v)    memset(h, v, sizeof h)
#define Forv(i, a)     for(auto& i : a)
#define For(i, a, b)   for(int i = a; i <= b; ++i)
#define Ford(i, a, b)  for(int i = a; i >= b; --i)
#define c_bit(i)     __builtin_popcountll(i)
#define Bit(mask, i)    ((mask >> i) & 1LL)
#define onbit(mask, i)  ((mask) bitor (1LL << i))
#define offbit(mask, i) ((mask) &~ (1LL << i))
#define TIME (1.0 * clock() / CLOCKS_PER_SEC)
using namespace std;
namespace std {
    template <typename T, int D>
    struct _vector : public vector <_vector <T, D - 1>> {
        static_assert(D >= 1, "Dimension must be positive!");
        template <typename... Args>
        _vector(int n = 0, Args... args) : vector <_vector <T, D - 1>> (n, _vector <T, D - 1> (args...)) {}
    };
    template <typename T> struct _vector <T, 1> : public vector <T> {
        _vector(int n = 0, const T& val = T()) : vector <T> (n, val) {}
    };
    template <class A, class B> bool minimize(A &a, B b){return a > b ? a = b, true : false;}
    template <class A, class B> bool maximize(A &a, B b){return a < b ? a = b, true : false;}
}
const int dx[] = {0, 0, +1, -1}, dy[] = {-1, +1, 0, 0}, LOG = 20, base = 311, inf = 1e9 + 5;
const int MAXN = 1e6 + 5;
const  ll  mod = 1e9 + 7;
const  ll   oo = 1e18;

#define int long long

ll a, b; string x;
ll dp[25][25][25][2];

string numbertostring (ll x){
    string res = "";
    while(x) res += char(x % 10 + '0'), x /= 10;
    reverse(all(res));
    return res;
}

ll solve(int i, int j, int k, bool ok){
//    cerr << i << ' ' << j << ' ' << k << ' ' << ok << '\n';
    if (i == x.size()) return 1;
    if (~dp[i][j][k][ok]) return dp[i][j][k][ok];
    ll res = 0;
    int limit = (ok == 1) ? 9 : (x[i] - '0');
    For(cs, 0, limit){
        if (j != 10) {
            if (cs != j && cs != k)
                res += solve(i + 1, cs, j, ok | (cs < x[i] - '0'));
        } else {
//            if (i == 2 && j == 10) cerr << '*' << cs << '\n';
            if (cs) res += solve(i + 1, cs, k, ok | (cs < x[i] - '0'));
            else res += solve(i + 1, j, k, ok | (cs < x[i] - '0'));
        }
    }
    return dp[i][j][k][ok] = res;
}

void Solve() {
    cin >> a >> b;
    reset(dp, -1);
    x = numbertostring(b);
    ll ans = solve(0, 10, 10, 0);
    reset(dp, -1);
    x = numbertostring(a - 1);
    ans -= solve(0, 10, 10, 0);
    cout << ans << '\n';
}

signed main() {
    cin.tie(0) -> sync_with_stdio(0);
    if(fopen("BOI13_numbers.inp", "r")) {
        freopen("BOI13_numbers.inp", "r", stdin);
        freopen("BOI13_numbers.out", "w", stdout);
    }

    int t = 1;
//    cin >> t;
    while(t --) Solve();

    return 0;
}

Compilation message (stderr)

numbers.cpp: In function 'long long int solve(long long int, long long int, long long int, bool)':
numbers.cpp:50:11: 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]
   50 |     if (i == x.size()) return 1;
      |         ~~^~~~~~~~~~~
numbers.cpp: In function 'int main()':
numbers.cpp:81:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   81 |         freopen("BOI13_numbers.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
numbers.cpp:82:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |         freopen("BOI13_numbers.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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