#include<bits/stdc++.h>
#define IOS ios_base::sync_with_stdio(false);cin.tie();cout.tie();
#define all(x) x.begin(), x.end()
#define lnl long long
#define pq priority_queue
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define pb push_back
#define pp pop_back
#define F first
#define S second
using namespace std;
struct pos {
set<pair<int, int>> s[30];
};
pos s[61];
lnl dis[31][31];
char c[31][31];
int n, m;
void build() {
dis[0][0] = 1;
for (int i = 0; i <= 30; i++) {
for (int j = 0; j <= 30; j++) {
if (i) dis[i][j] += dis[i-1][j];
if (j) dis[i][j] += dis[i][j-1];
}
}
}
void init() {
cin >> n >> m;
for (int i = 0; i < n; i++)
for (int j = 0; j < m; j++)
cin >> c[i][j];
n--; m--;
}
int calc(int i, int j) {
int ans = 0;
for (auto p: s[i].s[j]) {
ans += dis[n-p.F][m-p.S];
}
return ans;
}
void put(int i, int j) {
for (auto p: s[i].s[j]) {
if (p.F < n) s[i+1].s[c[p.F+1][p.S]-'a'].insert({p.F+1, p.S});
if (p.S < m) s[i+1].s[c[p.F][p.S+1]-'a'].insert({p.F, p.S+1});
}
}
void solve () {
build();
init();
lnl k; cin >> k;
string ans = "";
s[0].s[c[0][0]-'a'].insert({0, 0});
for (int i = 0; i <= n+m+1; i++) {
for (int j = 0; j < 26; j++) {
int x = calc(i, j);
// cout << i << ' ' << j << ' ' << x << ' ' << k << '\n';
if (x >= k) {
ans += j + 'a';
put(i, j);
break ;
}
k -= x;
}
}
cout << ans;
}
int main() {IOS solve(); return 0;}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
336 KB |
Output is correct |
| 2 |
Correct |
1 ms |
336 KB |
Output is correct |
| 3 |
Correct |
1 ms |
336 KB |
Output is correct |
| 4 |
Incorrect |
1 ms |
336 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
