#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
constexpr bool typetest = 0;
constexpr int N = 30 + 2;
int m, n;
int x[] = {0, 1},
y[] = {1, 0};
string s[N];
ll dp[N][N], k;
void Read()
{
cin >> m >> n;
for (int i = 1; i <= m; ++i)
{
cin >> s[i];
s[i] = " " + s[i];
}
cin >> k;
}
void BFS(int x, int y)
{
queue<pair<int, int>> s;
dp[x][y] = 1;
s.emplace(x, y);
while (s.size())
{
auto c = s.front();
s.pop();
if (c.first > 1)
{
if (!dp[c.first - 1][c.second])
s.emplace(c.first - 1, c.second);
dp[c.first - 1][c.second] += dp[c.first][c.second];
if (dp[c.first - 1][c.second] > 1e18)
dp[c.first - 1][c.second] = 2e18;
}
if (c.second > 1)
{
if (!dp[c.first][c.second - 1])
s.emplace(c.first, c.second - 1);
dp[c.first][c.second - 1] += dp[c.first][c.second];
if (dp[c.first][c.second - 1] > 1e18)
dp[c.first][c.second - 1] = 2e18;
}
}
}
void Solve()
{
BFS(m, n);
int a(1), b(1);
while (a != m || b != n)
{
cout << s[a][b];
if (a == m)
++b;
else if (b == n)
++a;
else
{
int d[] = {0, 1};
if (s[a + x[d[0]]][b + y[d[0]]] > s[a + x[d[1]]][b + y[d[1]]])
swap(d[0], d[1]);
if (dp[a + x[d[0]]][b + y[d[0]]] >= k)
{
a += x[d[0]];
b += y[d[0]];
}
else
{
k -= dp[a + x[d[0]]][b + y[d[0]]];
a += x[d[1]];
b += y[d[1]];
}
}
}
cout << s[a][b];
}
int32_t main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t(1);
if (typetest)
cin >> t;
for (int _ = 1; _ <= t; ++_)
{
Read();
Solve();
}
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
204 KB |
Output is correct |
| 2 |
Correct |
1 ms |
204 KB |
Output is correct |
| 3 |
Incorrect |
1 ms |
204 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
