| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 207805 | tri | The Kingdom of JOIOI (JOI17_joioi) | C++11 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
#define pb push_back
#define f first
#define s second
const int MAXN = 2000 + 10;
int H, W;
int grid[MAXN][MAXN];
int taken[MAXN][MAXN];
inline int lin(int i, int j) {
return i * W + j;
}
inline pi dLin(int x) {
return {x / W, x % W};
}
inline bool check(int i, int j) {
if (i - 1 >= 0 && !taken[i - 1][j]) {
return false;
}
if (j - 1 >= 0 && !taken[i][j - 1]) {
return false;
}
return true;
}
// compute min cost assuming TL-BR groups and that TL group is smaller
int compute() {
memset(taken, 0, sizeof(taken));
vi nums;
int cur = grid[0][0];
for (int i = 0; i < H; i++) {
for (int j = 0; j < W; j++) {
if (grid[i][j] >= cur) {
nums.pb(grid[i][j]);
}
}
}
sort(nums.begin(), nums.end());
nums.erase(unique(nums.begin(), nums.end()), nums.end());
priority_queue<pi, vector<pi>, greater<pi>> q;
q.push({cur, lin(0, 0)});
multiset<int> oth;
for (int i = 0; i < H; i++) {
for (int j = 0; j < W; j++) {
oth.insert({grid[i][j], lin(i, j)});
}
}
int cMin = cur;
int cMax = cur;
int ans = 1e9;
for (int uBI = 0; uBI < nums.size(); uBI++) {
int uB = nums[uBI];
while (q.size()) {
pi nxt = q.top();
if (nxt.f > uB) {
break;
}
q.pop();
int x = nxt.s;
pi coor = dLin(x);
int cV = grid[coor.f][coor.s];
oth.erase({cV, lin(coor.f, coor.s)});
cMin = min(cMin, cV);
cMax = max(cMax, cV);
taken[coor.f][coor.s] = true;
if (coor.f + 1 < H && check(coor.f + 1, coor.s)) {
q.push({grid[coor.f + 1][coor.s], lin(coor.f + 1, coor.s)});
}
if (coor.s + 1 < W && check(coor.f, coor.s + 1)) {
q.push({grid[coor.f][coor.s + 1], lin(coor.f, coor.s + 1)});
}
}
if (oth.size()) {
int cost = cMax - cMin;
cost = max(cost, (--oth.end())->f - oth.begin()->f);
ans = min(ans, cost);
}
}
return ans;
}
void flipMag() {
for (int i = 0; i < H; i++) {
for (int j = 0; j < W; j++) {
grid[i][j] = 1000000001 - grid[i][j];
}
}
}
void flip() {
for (int j = 0; j < W; j++) {
for (int i = 0; i < H / 2; i++) {
int tmp = grid[i][j];
grid[i][j] = grid[H - 1 - i][j];
grid[H - 1 - i][j] = tmp;
}
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> H >> W;
for (int i = 0; i < H; i++) {
for (int j = 0; j < W; j++) {
cin >> grid[i][j];
}
}
int ans = compute();
flipMag();
int ans2 = compute();
flip();
int ans3 = compute();
flipMag();
int ans4 = compute();
int fAns = min(min(ans, ans2), min(ans3, ans4));
cout << fAns << endl;
}