# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
492705 | SlavicG | Lucky Numbers (RMI19_lucky) | C++17 | 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 ll long long
#define forn(i,n) for(int i=0;i<n;i++)
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(),v.rend()
#define pb push_back
#define sz(a) (int)a.size()
const int N = 1e5 + 10, mod = 1e9 + 7;
int dp[N][10][2];
int calc(string& s){
int n = sz(s);
forn(i, N)forn(j, 10)forn(k, 2)dp[i][j][k] = 0;
for(int d = 1;d <= s[0] - '0'; ++d){
dp[0][d][d < s[0] - '0'] = 1;
}
for(int i = 1;i < n; ++i){
for(int lst = 0; lst <= 9; ++ lst){
for(int cur = 0;cur <= 9; ++cur){
if(lst == 1 && cur == 3)continue;
if(cur < s[i] - '0'){
dp[i][cur][1] += dp[i - 1][lst][0];
dp[i][cur][1] %= mod;
dp[i][cur][1] += dp[i - 1][lst][1];
dp[i][cur][1] %= mod;
}else if(cur == s[i] - '0'){
dp[i][cur][1] += dp[i - 1][lst][1];
dp[i][cur][1] %= mod;
dp[i][cur][0] += dp[i - 1][lst][0];
dp[i][cur][0] %= mod;
}else{
dp[i][cur][1] += dp[i - 1][lst][1];
dp[i][cur][1] %= mod;
}
}
}
}
int ans = 0;
for(int i = 0;i <= 9; ++i){
ans += (dp[n - 1][i][0] + dp[n - 1][i][1]) % mod;
ans %= mod;
}
return (ans + 1) % mod;
}
int cnt(string& s){
int ans = calc(s);
string a = "9";
while(sz(a) < sz(s)){
ans += calc(a);
ans %= mod;
a += '9';
}
return ans;
}
void solve()
{
int n, q;
cin >> n >> q >> s;
assert(q == 0);
cout << cnt(s) << "\n";
}
int32_t main(){
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
int t = 1;
//cin >> t;
while(t--)
{
solve();
}
}