Submission #636887

#	Time	Username	Problem	Language	Result	Execution time	Memory
636887		ogibogi2004	Lucky Numbers (RMI19_lucky)	C++14	46 / 100	411 ms	1744 KiB

lucky

#include<bits/stdc++.h>
using namespace std;
#define ll long long
const ll mod=1e9+7;
const ll MAXN=1e5+6;
ll dp[MAXN];
int n,q;
ll a[MAXN];
ll solve(int l,int r)
{
    ll ans=0;
    for(int i=l;i<=r;i++)
    {
        if(i>l+1&&a[i-2]==1&&a[i-1]==3)break;
        ans+=a[i]*dp[r-i];
        if(a[i]>1&&i<r)ans-=dp[r-i-1];
        if(i!=l&&a[i-1]==1&&a[i]>3)ans-=dp[r-i];
        while(ans<0)ans+=mod;
        ans%=mod;
        //cout<<i<<" "<<a[i]<<" "<<ans<<endl;
    }
    bool flag=1;
    for(int i=l;i+1<=r;i++)
    {
        if(a[i]==1&&a[i+1]==3)flag=0;
    }
    if(flag)ans++;
    ans%=mod;
    return ans;
}
void precompute()
{
    dp[0]=1;
    dp[1]=10;
    for(int i=2;i<MAXN;i++)
    {
        dp[i]=dp[i-1]*10ll-dp[i-2];
        dp[i]+=mod;
        dp[i]%=mod;
    }
}
int main()
{
    ios_base::sync_with_stdio();
    cin.tie(NULL);
    cout.tie(NULL);
    cin>>n>>q;
    precompute();
    for(int i=1;i<=n;i++)
    {
        char c;
        cin>>c;
        a[i]=c-'0';
    }
    cout<<solve(1,n)<<endl;
    for(int i=0;i<q;i++)
    {
        int t,x,y;
        cin>>t>>x>>y;
        if(t==1)cout<<solve(x,y)<<endl;
        else a[x]=y;
    }
return 0;
}

• Subtask 1: 14 / 14
• Subtask 2: 14 / 14
• Subtask 3: 9 / 9
• Subtask 4: 0 / 27
• Subtask 5: 9 / 9
• Subtask 6: 0 / 27