#include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;
const int N = 2000 + 3, inf = 1e9 + 7;
int h, w;
int a[N][N];
int prf_ma[N][N], prf_mi[N][N];
int suf_ma[N][N], suf_mi[N][N];
int f[3][N];
bool check(int diff) {
for (int i = 1; i <= h; ++i) {
int lo(1), hi(w), m;
while (lo <= hi) {
m = (lo + hi) >> 1;
if (prf_ma[i][m] - prf_mi[i][m] <= diff)
lo = m + 1;
else hi = m - 1;
}
f[0][i] = lo - 1;
}
f[1][0] = f[2][h + 1] = inf;
for (int i = 1; i <= h; ++i) f[1][i] = min(f[0][i], f[1][i - 1]);
for (int i = h; i >= 1; --i) f[2][i] = min(f[0][i], f[2][i + 1]);
bool flag1(false), flag2(false);
for (int i = 1; i <= h; ++i) {
flag1 |= suf_ma[i][f[1][i] + 1] - suf_mi[i][f[1][i] + 1] > diff;
flag2 |= suf_ma[i][f[2][i] + 1] - suf_mi[i][f[2][i] + 1] > diff;
}
return !flag1 || !flag2;
}
int main() {
cin.tie(NULL)->sync_with_stdio(false);
cin >> h >> w;
for (int i = 1; i <= h; ++i) {
prf_mi[i][0] = suf_mi[i][w + 1] = inf;
for (int j = 1; j <= w; ++j) {
cin >> a[i][j];
prf_ma[i][j] = max(prf_ma[i][j - 1], a[i][j]);
prf_mi[i][j] = min(prf_mi[i][j - 1], a[i][j]);
}
for (int j = w; j; --j) {
suf_ma[i][j] = max(suf_ma[i][j + 1], a[i][j]);
suf_mi[i][j] = min(suf_mi[i][j + 1], a[i][j]);
}
}
int lo(0), hi(inf), m;
while (lo <= hi) {
m = (lo + hi) >> 1;
if (check(m))
hi = m - 1;
else lo = m + 1;
}
cout << hi + 1 << '\n';
}
/** /\_/\
* (= ._.)
* / >0 \>1
**/
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
460 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
460 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
460 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |