Submission #709214

#	Time	Username	Problem	Language	Result	Execution time	Memory
709214		myrcella	The Kingdom of JOIOI (JOI17_joioi)	C++17	100 / 100	3403 ms	54936 KiB

joioi

//by szh
#include<bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define pii pair<int,int>
#define pll pair<long long,long long>
#define pb push_back
#define debug(x) cerr<<#x<<"="<<x<<endl
#define pq priority_queue
#define inf 0x3f
#define rep(i,a,b) for (int i=a;i<(b);i++)
#define MP make_pair
#define SZ(x) (int(x.size()))
#define ll long long
#define mod 1000000007
#define ALL(x) x.begin(),x.end()
void inc(int &a,int b) {a=(a+b)%mod;}
void dec(int &a,int b) {a=(a-b+mod)%mod;}
int lowbit(int x) {return x&(-x);}
ll p0w(ll base,ll p) {ll ret=1;while(p>0){if (p%2ll==1ll) ret=ret*base%mod;base=base*base%mod;p/=2ll;}return ret;}

const int maxn = 2010;

int n,m;
int grid[maxn][maxn];
int mn=mod,mx;
int pos[maxn];
int ans = 0;

bool check(int dif) {
	//mn on the top
	int lst = n-1;
	rep(i,0,m) {
		int cur = -1;
		while (cur+1<=lst and grid[cur+1][i]-mn<=dif) cur++;
		pos[i] = cur;
		lst = cur;
	}
	bool ok = false;
	rep(j,0,m) {
		rep(i,pos[j]+1,n) if (mx-grid[i][j]>dif) ok=true;
	}
	if (!ok) return true;
	
	lst = n-1;
	for (int i=m-1;i>=0;i--) {
		int cur = -1;
		while (cur+1<=lst and grid[cur+1][i]-mn<=dif) cur++;
		pos[i] = cur;
		lst = cur;
	}
	ok = false;
	rep(j,0,m) {
		rep(i,pos[j]+1,n) if (mx-grid[i][j]>dif) ok=true;
	}
	if (!ok) return true;
	
	//mx on the top
	lst = n-1;
	rep(i,0,m) {
		int cur = -1;
		while (cur+1<=lst and mx-grid[cur+1][i]<=dif) cur++;
		pos[i] = cur;
		lst = cur;
	}
	ok = false;
	rep(j,0,m) {
		rep(i,pos[j]+1,n) if (grid[i][j]-mn>dif) ok=true;
	}
	if (!ok) return true;
	
	lst = n-1;
	for (int i=m-1;i>=0;i--) {
		int cur = -1;
		while (cur+1<=lst and mx-grid[cur+1][i]<=dif) cur++;
		pos[i] = cur;
		lst = cur;
	}
	ok = false;
	rep(j,0,m) {
		rep(i,pos[j]+1,n) if (grid[i][j]-mn>dif) ok=true;
	}
	
	return !ok;
}

int main() {
//	freopen("input.txt","r",stdin);	
	std::ios::sync_with_stdio(false);cin.tie(0);
	cin>>n>>m;
	rep(i,0,n)
		rep(j,0,m) cin>>grid[i][j],mn = min(mn,grid[i][j]),mx = max(mx,grid[i][j]);
	int l = 0,r=1e9;
	while (l<r) {
		int mid=l+r>>1;
		if (check(mid)) r=mid;
		else l=mid+1;
	}
	cout<<l;
	return 0;
}

Compilation message (stderr)

joioi.cpp: In function 'int main()':
joioi.cpp:97:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   97 |   int mid=l+r>>1;
      |           ~^~

• Subtask 1: 15 / 15
• Subtask 2: 45 / 45
• Subtask 3: 40 / 40