#include "bits/stdc++.h"
using namespace std;
void solve() {
int n, m;
cin >> n >> m;
vector<string> a(n);
for (int i = 0; i < n; i++) {
cin >> a[i];
}
vector<vector<long long>> dp(n, vector<long long> (m));
for (int i = n - 1; i >= 0; i--) {
for (int j = m - 1; j >= 0; j--) {
if (i == n - 1 && j == m - 1) {
dp[i][j] = 1;
} else {
if (i + 1 < n) {
dp[i][j] += dp[i + 1][j];
}
if (j + 1 < m) {
dp[i][j] += dp[i][j + 1];
}
}
}
}
long long k;
cin >> k;
vector<vector<long long>> tmp(n, vector<long long> (m));
tmp[0][0] = 1;
for (int s = 0; s <= n + m - 2; s++) {
vector<pair<int, int>> pos;
for (int i = 0; i < n; i++) {
int j = s - i;
if (j >= 0 && j < m && tmp[i][j]) {
pos.push_back({i, j});
}
}
cout << a[pos[0].first][pos[0].second];
if (s == n + m - 2) {
break;
}
vector<long long> cnt(26);
for (auto [x, y] : pos) {
if (x + 1 < n) {
cnt[a[x + 1][y] - 'a'] += tmp[x][y] * dp[x + 1][y];
}
if (y + 1 < m) {
cnt[a[x][y + 1] - 'a'] += tmp[x][y] * dp[x][y + 1];
}
}
int ch = 0;
while (cnt[ch] < k) {
k -= cnt[ch];
ch++;
}
for (auto [x, y] : pos) {
if (x + 1 < n && a[x + 1][y] - 'a' == ch) {
tmp[x + 1][y] += tmp[x][y];
}
if (y + 1 < m && a[x][y + 1] - 'a' == ch) {
tmp[x][y + 1] += tmp[x][y];
}
}
}
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t = 1;
// cin >> t;
while (t--) {
solve();
}
}
# |
결과 |
실행 시간 |
메모리 |
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 |
Correct |
1 ms |
364 KB |
Output is correct |
5 |
Correct |
1 ms |
504 KB |
Output is correct |
6 |
Correct |
1 ms |
336 KB |
Output is correct |
7 |
Correct |
1 ms |
336 KB |
Output is correct |
8 |
Correct |
1 ms |
336 KB |
Output is correct |
9 |
Correct |
1 ms |
336 KB |
Output is correct |
10 |
Correct |
1 ms |
464 KB |
Output is correct |
11 |
Correct |
1 ms |
504 KB |
Output is correct |
12 |
Correct |
1 ms |
336 KB |
Output is correct |
13 |
Correct |
1 ms |
336 KB |
Output is correct |
14 |
Correct |
1 ms |
336 KB |
Output is correct |
15 |
Correct |
1 ms |
336 KB |
Output is correct |
16 |
Correct |
1 ms |
336 KB |
Output is correct |
17 |
Correct |
1 ms |
336 KB |
Output is correct |
18 |
Correct |
1 ms |
336 KB |
Output is correct |
19 |
Correct |
1 ms |
336 KB |
Output is correct |
20 |
Correct |
1 ms |
336 KB |
Output is correct |