#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll comb[63][33];
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;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
3 ms |
384 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |