Käännöt

#include <iostream>
#include <vector>
#include <map>
#include <cmath>
#include <utility>
#include <set>

using namespace std;

typedef long long LL;

string s;
LL n;
LL mod = 1e9 + 7;

/*
LL fact(LL x){
    LL ans = 1;
    for(int i = 1; i <= x; i++)
        ans = (ans * i) % mod;
    return ans;
}

LL nCr(LL m, LL k){
    if(k > m) return 0;
    return fact(m)/(fact(k)*(fact(m-k)));
}
*/

vector<LL> p10;

LL power(LL base, LL exp){
    LL ans = 1;
    for(LL i = 0; i < exp; i++){
        ans = (ans * base) % mod;
    }
    return ans;
}

LL f(LL i){
    LL ans = 0;
    for(LL p = 0; p <= n-1; p++){
        LL involved;
        if(i + p < n) involved = min(i+1,p+1);
        else involved = min(n-i, n-p);
        
        LL not_involved = ((p*p - p)/2 + p + (i*i - i)/2 + i);
            
        //cout << i << " " << p << ": " << involved << " " << not_involved << endl;
            
        ans = (ans + p10[p] * (s[i]-'0') * involved) % mod;
        if(i + p == n-1)
            ans = (ans + (p10[p] * (s[i]-'0')) * not_involved) % mod;
    }
    return ans;
    /*return (s[i] - '0') * ((1/81.0)*(9*pow(10,i+1)*i + pow(2,i+4)*pow(5,i+1) + 1) +
                           (1/9.0) * (pow(10,n) - pow(10,i+1)) * (i+1) ); */
}

int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(0);
    cin >> s;
    n = s.size();
    
    p10.push_back(1);
    for(int i = 1; i < n + 100; i++){
        p10.push_back((p10.back()*10) % mod);
    }
    
    LL ans = 0;
    for(int i = 0; i < n; i++){
        LL x = f(i);
        //cout << x << endl;
        ans = (ans + x) % mod;
    }
    cout << ans << endl;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 12

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 14

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 15

Group: 3

Verdict: TIME LIMIT EXCEEDED