#include <bits/stdc++.h>
using namespace std;
#define EmiliaMyWife ios::sync_with_stdio(0); cin.tie(0);
using ll = int64_t;
using ull = uint64_t;
using uint = uint32_t;
using ld = long double;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
const ll LINF = ll(4e48) + ll(2e15);
const double EPS = 1e-9;
static int LamyIsCute = []() {
EmiliaMyWife
return 48763;
}();
signed main() {
int n, m;
cin >> n >> m;
vector<vector<int>> arr(n + 1, vector<int>(m + 1));
int max_val = -INF, min_val = INF;
for(int i = 1; i <= n; i++)
for(int j = 1; j <= m; j++) {
cin >> arr[i][j];
max_val = max(max_val, arr[i][j]);
min_val = min(min_val, arr[i][j]);
}
vector<pair<int, int>> dp(n + 1);
auto rot = [&]() {
reverse(arr.begin(), arr.end());
};
auto go = [&](int k) {
dp[0] = {0, m};
for(int i = 1; i <= n; i++) {
vector<int> suf_min(m + 1);
for(int j = m; j; j--) {
suf_min[j] = arr[i][j];
if(j + 1 <= m)
suf_min[j] = min(suf_min[j], suf_min[j + 1]);
}
dp[i] = {INF, -INF};
for(int j = 0, mx = 0; j <= m; j++) {
mx = max(mx, arr[i][j]);
int r = (j < m ? suf_min[j + 1] : INF);
if(mx <= min_val + k && max_val - k <= r && dp[i - 1].first <= j) {
dp[i].first = min(dp[i].first, j);
dp[i].second = max(dp[i].second, j);
}
}
}
if(dp[n].first <= dp[n].second && dp[n].second > 0)
return true;
dp[0] = {0, m};
for(int i = 1; i <= n; i++) {
vector<int> suf_max(m + 1);
for(int j = m; j; j--) {
suf_max[j] = arr[i][j];
if(j + 1 <= m)
suf_max[j] = max(suf_max[j], suf_max[j + 1]);
}
dp[i] = {INF, -INF};
for(int j = 0, mn = 0; j <= m; j++) {
mn = min(mn, arr[i][j]);
int r = (j < m ? suf_max[j + 1] : -INF);
if(r <= min_val + k && max_val - k <= mn && dp[i - 1].first <= j) {
dp[i].first = min(dp[i].first, j);
dp[i].second = max(dp[i].second, j);
}
}
}
if(dp[n].first <= dp[n].second && dp[n].second > 0)
return true;
return false;
};
auto check = [&](int k) {
bool ok = false;
for(int i = 0; i < 2; i++)
ok |= go(k), rot();
return ok;
};
int l = 0, r = INF;
while(l < r) {
int m = l + r >> 1;
if(check(m))
r = m;
else
l = m + 1;
}
cout << l << '\n';
}
Compilation message
joioi.cpp: In function 'int main()':
joioi.cpp:89:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
89 | int m = l + r >> 1;
| ~~^~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
312 KB |
Output is correct |
| 2 |
Incorrect |
1 ms |
204 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
312 KB |
Output is correct |
| 2 |
Incorrect |
1 ms |
204 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
312 KB |
Output is correct |
| 2 |
Incorrect |
1 ms |
204 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
