oj.uz

답안 #239028

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
239028 2020-06-14T07:18:06 Z VEGAnn Mate (COCI18_mate) C++14
100 / 100
 1135 ms 21500 KB 
#include <bits/stdc++.h>
//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("-O3")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("fast-math")
//#pragma GCC optimize("no-stack-protector")
#define i2 array<int,2>
#define PB push_back
#define all(x) x.begin(),x.end()
#define sz(x) ((int)x.size())
using namespace std;
typedef long long ll;
const int N = 2010;
const ll OO = 1e18;
const int md = int(1e9) + 7;
vector<int> ps[26];
string s, st;
int n, C[N][N];
ll cnt[N][26], ans;

int sum(int x, int y){
    x += y;
    if (x >= md)
        x -= md;
    return x;
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);

#ifdef _LOCAL
    freopen("in.txt","r",stdin);
#endif // _LOCAL

    cin >> s;
    n = sz(s);

    for (int i = 0; i < n; i++) {
        ps[s[i] - 'a'].PB(i);

        for (int j = i + 1; j < n; j++)
            cnt[i][s[j] - 'a']++;
    }

    C[0][0] = 1;

    for (int i = 1; i <= n; i++){
        C[i][0] = C[i][i] = 1;

        for (int j = 1; j < n; j++)
            C[i][j] = sum(C[i - 1][j], C[i - 1][j - 1]);
    }

    int qq; cin >> qq;

    for (; qq; qq--){
        int d; cin >> d >> st;

        d -= 2;

        int ch = (st[1] - 'a'), C1 = (st[0] - 'a');

        ans = 0;

        for (int i : ps[C1]) {
            if (cnt[i][ch] == 0) break;

            (ans += cnt[i][ch] * C[i][d]) %= md;
        }

        cout << ans << '\n';
    }

    return 0;
}

Subtask #1
100.0 / 100.0

# 결과 실행 시간 메모리 Grader output
1 Correct 11 ms 640 KB Output is correct
2 Correct 9 ms 640 KB Output is correct
3 Correct 9 ms 640 KB Output is correct
4 Correct 14 ms 640 KB Output is correct
5 Correct 41 ms 2296 KB Output is correct
6 Correct 49 ms 2424 KB Output is correct
7 Correct 37 ms 2176 KB Output is correct
8 Correct 37 ms 2108 KB Output is correct
9 Correct 1135 ms 21500 KB Output is correct
10 Correct 1124 ms 21496 KB Output is correct