#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
#define FOR(i, x, y) for(ll i=x; i<y; i++)
#define FORNEG(i, x, y) for(ll i=x; i>y; i--)
#define fast() ios_base::sync_with_stdio(false);cin.tie(NULL)
ll n,m;
ll grid[2001][2001];
ll grid2[2001][2001];
ll mx = -1;
ll minmaxl[2001][2001];
ll minmaxr[2001][2001];
void setup(){
FOR(i,0,n){
FOR(j,0,m){
minmaxl[i][j] = 1000000000;
minmaxr[i][j] = 1000000000;
}
}
FORNEG(i,n-1,-1){
minmaxl[i][0] = grid[i][0];
FOR(j,1,m){
minmaxl[i][j] = min(minmaxl[i][j-1], grid[i][j]);
}
if (i!=n-1){
FOR(j,0,m){
minmaxl[i][j] = min(minmaxl[i][j], minmaxl[i+1][j]);
}
}
}
FORNEG(i,n-1,-1){
minmaxr[i][m-1] = grid[i][m-1];
FORNEG(j,m-2,-1){
minmaxr[i][j] = min(minmaxr[i][j+1], grid[i][j]);
}
if (i != n-1){
FOR(j,m-1,-1){
minmaxr[i][j] = min(minmaxr[i][j], minmaxr[i+1][j]);
}
}
}
}
bool check(ll a){
ll mini = 1000000000;
ll maxi = -1;
FOR(i,0,n){
FOR(j,0,m){
if (mx-minmaxl[i][j] > a){
mini = min(mini, grid[i][j]);
maxi = max(maxi, grid[i][j]);
}
}
}
if (maxi - mini <= a) return true;
mini = 1000000000;
maxi = -1;
FOR(i,0,n){
FOR(j,0,m){
if (mx-minmaxr[i][j] > a){
mini = min(mini, grid[i][j]);
maxi = max(maxi, grid[i][j]);
}
}
}
if (maxi - mini <= a) return true;
return false;
}
int main(){
cin >> n >> m;
FOR(i,0,n){
FOR(j,0,m){
cin >> grid[i][j];
mx = max(mx, grid[i][j]);
grid2[n-i-1][m-j-1] = grid[i][j];
}
}
setup();
ll lo = 0;
ll hi = mx;
while (lo<hi){
ll mid = (lo+hi)/2;
if (check(mid)){
hi = mid;
}
else{
lo = mid+1;
}
}
ll ans = lo;
FOR(i,0,n) FOR(j,0,m) grid[i][j] = grid2[i][j];
setup();
lo = 0;
hi = mx;
while (lo<hi){
ll mid = (lo+hi)/2;
if (check(mid)){
hi = mid;
}
else{
lo = mid+1;
}
}
cout << min(ans,lo);
}
Compilation message
joioi.cpp: In function 'void setup()':
joioi.cpp:46:54: warning: array subscript -2 is below array bounds of 'll [2001]' {aka 'long long int [2001]'} [-Warray-bounds]
46 | minmaxr[i][j] = min(minmaxr[i][j], minmaxr[i+1][j]);
| ~~~~~~~~~~~~~~^
joioi.cpp:46:37: warning: array subscript -2 is below array bounds of 'll [2001]' {aka 'long long int [2001]'} [-Warray-bounds]
46 | minmaxr[i][j] = min(minmaxr[i][j], minmaxr[i+1][j]);
| ~~~~~~~~~~~~^
joioi.cpp:46:54: warning: array subscript -2 is below array bounds of 'll [2001]' {aka 'long long int [2001]'} [-Warray-bounds]
46 | minmaxr[i][j] = min(minmaxr[i][j], minmaxr[i+1][j]);
| ~~~~~~~~~~~~~~^
joioi.cpp:46:37: warning: array subscript -2 is below array bounds of 'll [2001]' {aka 'long long int [2001]'} [-Warray-bounds]
46 | minmaxr[i][j] = min(minmaxr[i][j], minmaxr[i+1][j]);
| ~~~~~~~~~~~~^
joioi.cpp:46:17: warning: array subscript -2 is below array bounds of 'll [2001]' {aka 'long long int [2001]'} [-Warray-bounds]
46 | minmaxr[i][j] = min(minmaxr[i][j], minmaxr[i+1][j]);
| ~~~~~~~~~~~~^
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |