# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
270352 | Hehehe | Palindrome-Free Numbers (BOI13_numbers) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define dbg(x) cout << #x << '=' << x << '\n';
#define ll long long
#define x first
#define y second
#define pi pair <int, int>
#define vi vector <int>
#define L nod<<1
#define R ((nod<<1)|1)
#define mp make_pair
const ll mod = 1000000007;
const ll nmax=1000003;
#define int ll
int a, b;
int dp[20][11][11][2];
int f(int x){
memset(dp, 0, sizeof(dp));
if(x <= 9)return x + 1;
int ans = 0;
vector<int>v;
string s = to_string(x);
for(auto it : s)v.push_back(it - '0');
int n = sz(v);
for(int i=0; i<n; i++){
dp[i][10][10][0]=1;
if(i==0){
for(int next=1; next<=9; next++){
if(next>v[i]) break;
else dp[i][10][next][(next==v[i])]=1;
}
}
else if(i==1){
for(int next=1; next<=9; next++){
dp[i][10][next][0]=1;
}
for(int xd2=1; xd2<=9; xd2++){
for(int eq=0; eq<2; eq++){
for(int next=0; next<=9; next++){
if((eq && next>v[i]) || xd2==10) break;
int ctrl=(eq&(next==v[i]));
if(next!=xd2) dp[i][xd2][next][ctrl]+=dp[i-1][10][xd2][eq];
}
}
}
continue;
}
else{
for(int next=1; next<=9; next++){
dp[i][10][next][0]=1;
}
for(int xd2=1; xd2<=9; xd2++){
for(int next=0; next<=9; next++){
if(next!=xd2) dp[i][xd2][next][0]+=dp[i-1][10][xd2][0];
}
}
for(int xd1=0; xd1<=9; xd1++){
for(int xd2=0; xd2<=9; xd2++){
for(int eq=0; eq<2; eq++){
for(int next=0; next<=9; next++){
if(eq && next>v[i]) break;
int ctrl=(eq&(next==v[i]));
if(next!=xd1 && next!=xd2) dp[i][xd2][next][ctrl]+=dp[i-1][xd1][xd2][eq];
}
}
}
}
}
}
//for(int i=0; i<v.size(); i++){
for(int xd1=0; xd1<=10; xd1++){
for(int xd2=0; xd2<=10; xd2++){
for(int eq=0; eq<2; eq++){
ans+=dp[n-1][xd1][xd2][eq];
}
//}
}
}
return ans;
}
int32_t main(){
ios_base :: sync_with_stdio(0); cin.tie(); cout.tie();
//while(cin>>a) cout<<f(a)<<endl;
cin>>a>>b;
a--;
cout<<f(b)-f(a);
}