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Submission #101093

# Submission time Handle Problem Language Result Execution time Memory
101093 2019-03-16T13:00:58 Z choikiwon K-th path (IZhO11_kthpath) C++17
100 / 100
 65 ms 512 KB 
#include<bits/stdc++.h>
using namespace std;

typedef long long ll;

ll comb[63][63];

int N, M;
ll K;
char G[33][33];
string ans;

ll dp[2][33][33];
ll calc() {
    for(int x = (int)ans.size() - 1; x >= 0; x--) {
        int c = x & 1;
        int p = c ^ 1;

        for(int i = 0; i < N; i++) {
            for(int j = 0; j < M; j++) {
                dp[c][i][j] = 0;
                if(G[i][j] != ans[x]) continue;
                if(x == (int)ans.size() - 1) {
                    dp[c][i][j] = comb[N + M - 2 - i - j][M - 1 - j];
                    continue;
                }
                if(i < N - 1) dp[c][i][j] += dp[p][i + 1][j];
                if(j < M - 1) dp[c][i][j] += dp[p][i][j + 1];
            }
        }
    }
    return dp[0][0][0];
}

int main() {
    comb[0][0] = 1;
    for(int i = 1; i < 63; i++) {
        comb[i][0] = 1;
        for(int j = 1; j <= i; j++) {
            comb[i][j] = comb[i - 1][j - 1] + comb[i - 1][j];
        }
    }

    std::ios::sync_with_stdio(false);

    cin >> N >> M;

    for(int i = 0; i < N; i++) {
        for(int j = 0; j < M; j++) {
            cin >> G[i][j];
        }
    }

    cin >> K;

    for(int i = 0; i < N + M; i++) {
        for(int j = 0; j < 26; j++) {
            ans.push_back('a' + j);

            ll t = calc();
            if(K <= t) break;
            K -= t;
            ans.pop_back();
        }
    }

    cout << ans;
}

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 3 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 3 ms 512 KB Output is correct
6 Correct 3 ms 384 KB Output is correct
7 Correct 6 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 3 ms 384 KB Output is correct
10 Correct 17 ms 384 KB Output is correct
11 Correct 8 ms 384 KB Output is correct
12 Correct 17 ms 384 KB Output is correct
13 Correct 30 ms 384 KB Output is correct
14 Correct 36 ms 432 KB Output is correct
15 Correct 65 ms 384 KB Output is correct
16 Correct 65 ms 420 KB Output is correct
17 Correct 56 ms 504 KB Output is correct
18 Correct 54 ms 384 KB Output is correct
19 Correct 59 ms 384 KB Output is correct
20 Correct 46 ms 384 KB Output is correct