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Submission #218283

# Submission time Handle Problem Language Result Execution time Memory
218283 2020-04-01T19:42:01 Z dolphingarlic Trener (COCI20_trener) C++14
110 / 110
 225 ms 18296 KB 
/*
COCI 2020 Trener
- Notice that we only need to check consecutive words and that only the first and last
  letters can differ
- We just use a map and some dp to solve this
- Complexity: O(NK^2)
*/

#include <bits/stdc++.h>
#define FOR(i, x, y) for (int i = x; i < y; i++)
typedef long long ll;
using namespace std;
 
const ll M = 1e9 + 7;

ll dp[1501];

map<string, ll> mp;
 
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, k;
    cin >> n >> k;
    FOR(i, 1, n + 1) FOR(j, 1, k + 1) {
        string s;
        cin >> s;
        dp[j] = (i > 1 ? mp[s.substr(0, i - 1)] + mp[s.substr(1, i - 1)] : 1);
        if (i > 1 && s.substr(0, i - 1) == s.substr(1, i - 1)) dp[j] -= mp[s.substr(1, i - 1)];
        if (dp[j] >= M) dp[j] -= M;
        mp[s] += dp[j];
        if (mp[s] >= M) mp[s] -= M;
    }
    ll ans = 0;
    FOR(i, 1, k + 1) {
        ans += dp[i];
        if (ans >= M) ans -= M;
    }
    cout << ans;
    return 0;
}

Subtask #1
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 384 KB Output is correct
2 Correct 4 ms 384 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct

Subtask #2
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 1536 KB Output is correct
2 Correct 15 ms 1536 KB Output is correct
3 Correct 15 ms 1536 KB Output is correct
4 Correct 8 ms 512 KB Output is correct
5 Correct 14 ms 1280 KB Output is correct
6 Correct 15 ms 1280 KB Output is correct
7 Correct 8 ms 512 KB Output is correct

Subtask #3
55.0 / 55.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 384 KB Output is correct
2 Correct 4 ms 384 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 15 ms 1536 KB Output is correct
6 Correct 15 ms 1536 KB Output is correct
7 Correct 15 ms 1536 KB Output is correct
8 Correct 8 ms 512 KB Output is correct
9 Correct 14 ms 1280 KB Output is correct
10 Correct 15 ms 1280 KB Output is correct
11 Correct 8 ms 512 KB Output is correct
12 Correct 220 ms 18168 KB Output is correct
13 Correct 225 ms 18168 KB Output is correct
14 Correct 213 ms 18172 KB Output is correct
15 Correct 215 ms 18296 KB Output is correct
16 Correct 53 ms 2300 KB Output is correct
17 Correct 202 ms 12920 KB Output is correct
18 Correct 194 ms 13048 KB Output is correct
19 Correct 191 ms 12924 KB Output is correct
20 Correct 198 ms 12952 KB Output is correct
21 Correct 190 ms 12920 KB Output is correct
22 Correct 58 ms 2296 KB Output is correct