Submission #549718

#	Time	Username	Problem	Language	Result	Execution time	Memory
549718		Pherokung	The Kingdom of JOIOI (JOI17_joioi)	C++14	0 / 100	3 ms	852 KiB

joioi

#include<bits/stdc++.h>
using namespace std;
#define N 2005
#define F first
#define S second
int n,m,a[N][N],b[N][N],ans=2e9;
typedef pair<int,int> pa;
 
pa cal(int n,int m,int v){
	bitset<N> dp[N];
	for(int i=0;i<=n;i++) dp[i] = 1;
	for(int i=0;i<=m;i++) dp[n+1][i] = 1;
	
	for(int i=n;i>0;i--) for(int j=1;a[i][j]<=v&&dp[i+1][j]&&dp[i][j-1];j++) dp[i][j]=1;
	
	int mx0=0,mx1=0,mn0=1e9,mn1=1e9;
	for(int i=1;i<=n;i++) for(int j=1;j<=m;j++){
		if(!dp[i][j]) mx0 = max(mx0,a[i][j]), mn0 = min(mn0,a[i][j]);
		else mx1 = max(mx1,a[i][j]), mn1 = min(mn1,a[i][j]);
	}
	if(!dp[n][1]) return {0,1e9};
	if(dp[1][m]) return {1e9,0};
//	printf(">> %d : %d %d %d %d\n",v,mx1,mn1,mx0,mn0);
	if(mn1 >= mn0) return {0,1e9};
	return {mx1-mn1,mx0-mn0};
}
 
int sol(int n,int m){
	int be = 0,ed = 1e9,ans=1e9;
	while(be <= ed){
		int mid = (be+ed)/2;
		pa V = cal(n,m,mid);
		ans = min(ans,max(V.F,V.S));
//		printf("%d : %d %d\n",mid,V.F,V.S);
		if(V.F > V.S) ed = mid-1;
		else be = mid+1;
	}
	return ans;
}
 
int main(){
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++) for(int j=1;j<=m;j++) scanf("%d",&a[i][j]);
	
    ans = min(ans,sol(n,m));
    
    for(int i=1;i<=n;i++) for(int j=1;j<=m;j++) b[i][j] = a[i][j];
    for(int i=1;i<=m;i++) for(int j=1;j<=n;j++) a[i][j] = b[n-j+1][i];
    ans = min(ans,sol(m,n));
    
	for(int i=1;i<=m;i++) for(int j=1;j<=n;j++) b[i][j] = a[i][j];
    for(int i=1;i<=n;i++) for(int j=1;j<=m;j++) a[i][j] = b[m-j+1][i];
    ans = min(ans,sol(n,m));
    
	for(int i=1;i<=n;i++) for(int j=1;j<=m;j++) b[i][j] = a[i][j];
    for(int i=1;i<=m;i++) for(int j=1;j<=n;j++) a[i][j] = b[n-j+1][i];
    ans = min(ans,sol(m,n));
 
	printf("%d",ans);
}
/*
4 4
1 12 6 11
11 10 2 14
10 1 9 20
4 17 19 10
 
3 4
1 1 1 1
1 1 9 2
2 2 2 2
 
3 4
2 2 2 2
9 2 1 1
1 1 1 1
*/

Compilation message (stderr)

joioi.cpp: In function 'int main()':
joioi.cpp:42:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |  scanf("%d%d",&n,&m);
      |  ~~~~~^~~~~~~~~~~~~~
joioi.cpp:43:51: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |  for(int i=1;i<=n;i++) for(int j=1;j<=m;j++) scanf("%d",&a[i][j]);
      |                                              ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 45
• Subtask 3: 0 / 40