2019牛客暑期多校训练营（第五场）

#include<bits/stdc++.h>

using namespace std;
int n;
int main(){
    int T;
    scanf("%d",&T);
    while (T--){
        scanf("%d",&n);
        for (int i=1;i<=n;i++){
            printf("%d",n);
        }
        printf("\n");
    }
}

 

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
char s[1000100];
ll mod;
struct node
{
    ll a[2][2];

    node operator*(const node &b) const
    {
        node res;
        for (int i = 0; i < 2; i++)
        {
            for (int j = 0; j < 2; j++)
            {
                res.a[i][j] = 0;
                for (int k = 0; k < 2; k++)
                {
                    res.a[i][j] = (res.a[i][j] + a[i][k] * b.a[k][j]) % mod;
                }
            }
        }
        return res;
    }
};

node pow(node b,ll c)
{
    node res;
    res.a[0][0] = 1;
    res.a[1][0] = 0;
    res.a[0][1] = 0;
    res.a[1][1] = 1;
    while (c)
    {
        if (c & 1)
        {
            res = res * b;
        }
        c >>= 1;
        b = b * b;
    }
    return res;
}

int main()
{
    ll a,b,x0,x1;
    scanf("%lld%lld%lld%lld",&x0,&x1,&a,&b);
    node f;
    f.a[0][0] = 0;
    f.a[1][0] = 1;
    f.a[0][1] = b;
    f.a[1][1] = a;
    node ans;
    ans.a[0][0]=1;
    ans.a[0][1]=0;
    ans.a[1][0]=0;
    ans.a[1][1]=1;
    scanf("%s",s);
    ll len=strlen(s);
    scanf("%lld",&mod);
    for (int i=0; i<len; i++)
    {
        ans=pow(ans,10)*pow(f,s[i]-'0');
    }
    printf("%lld\n",(x0*ans.a[0][0]+x1*ans.a[1][0])%mod);
}

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll mod=998244353;
const int N=3050;
ll C[N][N],n,m,dp[N],ans;
char s[1000000],t[1000000];
int main()
{
    for (int i=1; i<3050; i++)
    {
        C[i][0]=C[i][i]=1;
        for (int j=1; j<i; j++)
        {
            C[i][j]=(C[i-1][j]+C[i-1][j-1])%mod;
        }
    }
    int T;
    scanf("%d",&T);
    while (T--)
    {
        scanf("%lld%lld",&n,&m);
        scanf("%s",s+1);
        scanf("%s",t+1);

        for (int j=0; j<=m+1; j++)
        {
            dp[j]=0;
        }
        dp[1]=(s[n]>t[m]);
        for (int i=n-1; i>=1; i--)
        {
            for (int j=min(m,n-i+1); j>=1; j--)
            {
                if (s[i]>t[m-j+1])
                {
                    dp[j]=(dp[j]+C[n-i][j-1])%mod;
                    ////如果i位  s更大  ，可以由长度j-1任意首位递推
                }
                if (s[i]==t[m-j+1])
                {
                    dp[j]=(dp[j]+dp[j-1])%mod;
                }
            }
        }
        ans=dp[m];
        for (int i=1; i<=n; i++)
        {
            if (s[i]!='0')
            {
                for (int j=m; j+i<=n; j++)
                {
                    ans=(ans+C[n-i][j])%mod;
                }
            }
        }
        printf("%lld\n",(ans+mod)%mod);
    }
}