제출 #143649

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
143649		vladciuperceanu	Mate (COCI18_mate)	C++14	10 / 100	2069 ms	57608 KiB

mate

#include <iostream>
#include <cstring>
#define MOD 1000000007

using namespace std;

long long Q,d,i,j,comb[2005][2005],D[2005][30][30];
long long r[2005][30],poz[30][2005],sol[2005][30][30];
char s[2005],x,y;

int main()
{
    cin >> (s+1);
    int n = strlen((s+1));
    comb[0][0] = 1;
    for (i=1; i<=n; i++)
    {
        comb[i][0] = comb[i][i] = 1;
        for (j=1; j<i; j++)
            comb[i][j] = (comb[i-1][j-1]+comb[i-1][j])%MOD;
    }
    for (i=1; i<=n; i++)
        poz[s[i]-'a'][++poz[s[i]-'a'][0]] = i;
    for (i=n; i>=1; i--)
        for (j=0; j<26; j++)
            if (s[i] == 'a'+j)
                r[i][j] = 1+r[i+1][j];
            else
                r[i][j] = r[i+1][j];
    for (i=n; i>=1; i--)
        for (j=0; j<26; j++)
            for (int k=0; k<26; k++)
                if (s[i] == 'a'+j)
                    D[i][j][k] = r[i+1][k];
                else
                    D[i][j][k] = D[i+1][j][k];
    for (int l=2; l<=n; l++)
        for (j=0; j<26; j++)
            for (int t=1; t<=poz[j][0]; t++)
            {
                i = poz[j][t];
                if (i >= l-1)
                    for (int k=0; k<26; k++)
                        sol[l][j][k] += (D[i][j][k]*comb[i-1][l-2])%MOD;
            }
    cin >> Q;
    for (;Q--;)
    {
        cin >> d >> x >> y;
        cout << sol[d][x-'a'][y-'a'] << "\n";
    }
    return 0;
}

• Subtask 1: 10 / 100