oj.uz

답안 #143650

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
143650 2019-08-14T19:47:02 Z vladciuperceanu Mate (COCI18_mate) C++14
80 / 100
 2000 ms 56672 KB 
#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];
            if (comb[i][j] >= MOD)
                comb[i][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;
                        if (sol[l][j][k] >= MOD)
                            sol[l][j][k] -= MOD;
                    }
            }
    cin >> Q;
    for (;Q--;)
    {
        cin >> d >> x >> y;
        cout << sol[d][x-'a'][y-'a'] << "\n";
    }
    return 0;
}

Subtask #1
80.0 / 100.0

# 결과 실행 시간 메모리 Grader output
1 Correct 90 ms 1404 KB Output is correct
2 Correct 59 ms 1272 KB Output is correct
3 Correct 69 ms 1272 KB Output is correct
4 Correct 117 ms 1372 KB Output is correct
5 Correct 426 ms 5116 KB Output is correct
6 Correct 476 ms 5240 KB Output is correct
7 Correct 362 ms 5184 KB Output is correct
8 Correct 334 ms 4976 KB Output is correct
9 Execution timed out 2068 ms 56632 KB Time limit exceeded
10 Execution timed out 2071 ms 56672 KB Time limit exceeded