Submission #410786

#	Time	Username	Problem	Language	Result	Execution time	Memory
410786		Victor	Palindrome-Free Numbers (BOI13_numbers)	C++17	72.50 / 100	2 ms	332 KiB

numbers

#include <bits/stdc++.h>

using namespace std;

#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define per(i, a, b) for (int i = b - 1; i >= (a); --i)
#define trav(a, x) for (auto &a : x)

#define all(x) x.begin(), x.end()
#define sz(x) x.size()
#define pb push_back

#define umap unordered_map
#define uset unordered_set

typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef long long ll;

const int INF = 1'000'000'007;

string lo, hi;
ll memo[20][11][11][2][2];

ll dp(int num, int prev, int befprev, bool l_bound, bool u_bound) {
    if (num == sz(hi)) return 1;

    ll &ans = memo[num][prev][befprev][l_bound][u_bound];
    if(ans!=-1)return ans;

    ans = sz(lo) <= num;
    if (sz(lo) <= num) l_bound = 0;

    int start = l_bound ? lo[num] - '0' : 0, stop = u_bound ? hi[num] - '0' + 1 : 10;
    rep(i, start, stop) {
        if (i == prev || i == befprev) continue;
        ans += dp(num + 1, i, prev, l_bound & (i == lo[num] - '0'), u_bound & (i == hi[num] - '0'));
    }

    return ans;
}

int main() {
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);

    ll l,h;
    memset(memo, -1, sizeof(memo));
    cin >> l >> h;

    lo=to_string(l);
    hi=to_string(h);
    cout<<dp(0,10,10,1,1)<<endl;

    return 0;
}

Compilation message (stderr)

numbers.cpp: In function 'll dp(int, int, int, bool, bool)':
numbers.cpp:29:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |     if (num == sz(hi)) return 1;
      |             ^
numbers.cpp:34:18: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   34 |     ans = sz(lo) <= num;
      |                  ^
numbers.cpp:35:16: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   35 |     if (sz(lo) <= num) l_bound = 0;
      |                ^

• Subtask 1: 12.5 / 25
• Subtask 2: 60 / 75