#include <bits/stdc++.h>
#define fi first
#define se second
#define ryan bear
#define all(V) ((V).begin()), ((V).end())
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef long double ld;
typedef vector<int> vim;
typedef vector<ll> vlm;
int H, W;
int ar[2010][2010];
int Lmn[2010][2010], Lmx[2010][2010], Rmn[2010][2010], Rmx[2010][2010];
int lb[2010];
void init() {
for (int i=1; i<=H; i++) Lmn[i][0]=Rmn[i][W+1]=(1<<30);
for (int i=1; i<=W; i++) Lmn[0][i]=Rmn[H+1][i]=(1<<30);
for (int i=1; i<=H; i++) for (int j=1; j<=W; j++) {
Lmn[i][j]=min({ar[i][j], Lmn[i-1][j], Lmn[i][j-1]});
Lmx[i][j]=max({ar[i][j], Lmx[i-1][j], Lmx[i][j-1]});
}
for (int i=H; i>=1; i--) for (int j=W; j>=1; j--) {
Rmn[i][j]=min({ar[i][j], Rmn[i+1][j], Rmn[i][j+1]});
Rmx[i][j]=max({ar[i][j], Rmx[i+1][j], Rmx[i][j+1]});
}
}
int f(int v, int mn) {
int r=W;
int rn=(1<<30), rx=0;
for (int i=1; i<=H; i++) {
int u=upper_bound(Lmx[i]+1, Lmx[i]+W+1, mn+v)-Lmx[i];
r=min(r, u-1);
rn=min(rn, Rmn[i][u]);
rx=max(rx, Rmx[i][u]);
}
if (rn==(1<<30)) rn=0;
return (rx-rn<=v?1:0);
}
int solve() {
init();
int mx=0, st=0, mn=Lmn[H][W];
for (int i=H; i>=1; i--) {
for (int j=W; j>=1; j--) if (mn==ar[i][j]) { st=max(st, j); break; }
lb[i]=st; mx=max(mx, Lmx[i][st]);
}
int s=mx-mn, e=Lmx[H][W], ret;
int ans=(1<<30);
while (s<e) {
int md=(s+e)/2;
if (f(md, mn)) {
ans=md; e=md;
}
else s=md+1;
}
return ans;
}
int main() {
int ans;
scanf("%d %d", &H, &W);
for (int i=1; i<=H; i++) for (int j=1; j<=W; j++) scanf("%d", &ar[i][j]);
ans=solve();
for (int i=1; i<=H; i++) for (int j=1; j<=W; j++) {
if ((i-1)*H+j>(H*W)/2) break;
swap(ar[i][j], ar[H-i+1][W-j+1]);
}
ans=min(ans, solve());
printf("%d\n", ans);
return 0;
}
Compilation message
joioi.cpp: In function 'int solve()':
joioi.cpp:53:28: warning: unused variable 'ret' [-Wunused-variable]
int s=mx-mn, e=Lmx[H][W], ret;
^~~
joioi.cpp: In function 'int main()':
joioi.cpp:67:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &H, &W);
~~~~~^~~~~~~~~~~~~~~~~
joioi.cpp:68:57: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
for (int i=1; i<=H; i++) for (int j=1; j<=W; j++) scanf("%d", &ar[i][j]);
~~~~~^~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
504 KB |
Output is correct |
| 2 |
Incorrect |
2 ms |
504 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
504 KB |
Output is correct |
| 2 |
Incorrect |
2 ms |
504 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
504 KB |
Output is correct |
| 2 |
Incorrect |
2 ms |
504 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
