Submission #342340

#	Time	Username	Problem	Language	Result	Execution time	Memory
342340		jeroenodb	Palindrome-Free Numbers (BOI13_numbers)	C++14	100 / 100	1 ms	384 KiB

numbers

#include <iostream>
#include <vector>
#include <bitset>
#include <cassert>
#include <algorithm>
#include <cstring>
using namespace std;
#define all(x) begin(x),end(x)
typedef long long ll;
const int mxN = 1e5+1;
ll dp[18][11][11][2];
vector<int> dig;
ll recur(int i=0, int p=10, int pp=10, bool free=false) {
    if(i==dig.size()) return 1;
    if(dp[i][p][pp][free]) {
        return dp[i][p][pp][free]-1;
    }
    dp[i][p][pp][free]++;
    int limit = free?9:dig[i];
    for(int d=0;d<=limit;++d) {
            if(d==p or d==pp) continue;
            int tmp = d;
            if(p==10 and d==0) {
                tmp=10;
            }
            dp[i][p][pp][free]+=recur(i+1,tmp,p,free or d!=dig[i]);
    }
    return dp[i][p][pp][free]-1;

}
ll solve(ll a) {
    if(a==-1) return 0;
    memset(&dp[0][0][0][0], 0,sizeof(dp));
    dig.clear();
    while(a!=0) {
        dig.push_back(a%10);
        a/=10;
    }
    reverse(all(dig));
    return recur();
}
int main() {
    ll a,b; cin >> a >> b;
    cout << solve(b) - solve(a-1) << endl;
}

Compilation message (stderr)

numbers.cpp: In function 'll recur(int, int, int, bool)':
numbers.cpp:14:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |     if(i==dig.size()) return 1;
      |        ~^~~~~~~~~~~~

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