제출 #927733

#제출 시각아이디문제언어결과실행 시간메모리
927733andrei_boacaMisspelling (JOI22_misspelling)C++17
100 / 100
835 ms457772 KiB
#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
const int mod=1e9+7;
int n,m;
int lastmare[500005],lastmic[500005];
int dp[3][28][500005]; /// 0 -> egal, 1 -> mai mic, 2 -> mai mare
int spref[3][28][500005],ssuf[3][28][500005];
int rmq[2][21][500005]; /// 0 -> lastmic, 1 -> lastmare
int loga[500005];
int getmax(int tip,int l,int r)
{
    int lg=loga[r-l+1];
    return max(rmq[tip][lg][l],rmq[tip][lg][r-(1<<lg)+1]);
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int a,b;
        cin>>a>>b;
        if(a<b)
            lastmic[a]=max(lastmic[a],b);
        if(a>b)
            lastmare[b]=max(lastmare[b],a);
    }
    for(int i=1;i<=n;i++)
    {
        for(int bit=0;bit<=20;bit++)
            if((1<<bit)<=i)
                loga[i]=bit;
        rmq[0][0][i]=lastmic[i];
        rmq[1][0][i]=lastmare[i];
    }
    for(int tip=0;tip<=1;tip++)
        for(int j=1;j<=20;j++)
            for(int i=1;i<=n;i++)
            {
                rmq[tip][j][i]=rmq[tip][j-1][i];
                int poz=i+(1<<(j-1));
                if(poz<=n)
                    rmq[tip][j][i]=max(rmq[tip][j][i],rmq[tip][j-1][poz]);
            }
    for(int i=1;i<=26;i++)
        dp[2][i][1]=1;
    for(int tip=1;tip<=2;tip++)
    {
        int suma=0;
        for(int c=1;c<=26;c++)
        {
            suma=(suma+dp[tip][c][1])%mod;
            spref[tip][c][1]=(spref[tip][c][0]+suma)%mod;
        }
    }
    for(int tip=1;tip<=2;tip++)
    {
        int suma=0;
        for(int c=26;c>=1;c--)
        {
            suma=(suma+dp[tip][c][1])%mod;
            ssuf[tip][c][1]=(ssuf[tip][c][0]+suma)%mod;
        }
    }
    for(int i=2;i<=n;i++)
    {
        int pmare=i,pmic=i;
        /// mai mare
        int st=1;
        int dr=i-1;
        while(st<=dr)
        {
            int mij=(st+dr)/2;
            if(getmax(0,mij,i-1)<i)
            {
                pmare=mij;
                dr=mij-1;
            }
            else
                st=mij+1;
        }
        /// mai mic
        st=1;
        dr=i-1;
        while(st<=dr)
        {
            int mij=(st+dr)/2;
            if(getmax(1,mij,i-1)<i)
            {
                pmic=mij;
                dr=mij-1;
            }
            else
                st=mij+1;
        }
        for(int c=1;c<=26;c++)
        {
            dp[0][c][i]=(1LL*dp[0][c][i-1]+1LL*dp[1][c][i-1]+1LL*dp[2][c][i-1])%mod;

            int x=(spref[1][c-1][i-1]-spref[1][c-1][pmic-1]+mod)%mod;
            int y=(spref[2][c-1][i-1]-spref[2][c-1][pmic-1]+mod)%mod;
            dp[1][c][i]=(x+y)%mod;
            x=(ssuf[1][c+1][i-1]-ssuf[1][c+1][pmare-1]+mod)%mod;
            y=(ssuf[2][c+1][i-1]-ssuf[2][c+1][pmare-1]+mod)%mod;
            dp[2][c][i]=(x+y)%mod;
        }
        for(int tip=1;tip<=2;tip++)
        {
            int suma=0;
            for(int c=1;c<=26;c++)
            {
                suma=(suma+dp[tip][c][i])%mod;
                spref[tip][c][i]=(spref[tip][c][i-1]+suma)%mod;
            }
        }
        for(int tip=1;tip<=2;tip++)
        {
            int suma=0;
            for(int c=26;c>=1;c--)
            {
                suma=(suma+dp[tip][c][i])%mod;
                ssuf[tip][c][i]=(ssuf[tip][c][i-1]+suma)%mod;
            }
        }
    }
    int ans=0;
    for(int c=1;c<=26;c++)
    {
        ans=(ans+dp[0][c][n])%mod;
        ans=(ans+dp[1][c][n])%mod;
        ans=(ans+dp[2][c][n])%mod;
    }
    cout<<ans;
    return 0;
}
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...