Submission #334435

#	Time	Username	Problem	Language	Result	Execution time	Memory
334435		Kerim	Bomb (IZhO17_bomb)	C++17	100 / 100	697 ms	59500 KiB

bomb

#include "bits/stdc++.h"
#define MAXN 100009
#define INF 1000000007
#define mp(x,y) make_pair(x,y)
#define all(v) v.begin(),v.end()
#define pb(x) push_back(x)
#define wr cout<<"----------------"<<endl;
#define ppb() pop_back()
#define tr(ii,c) for(__typeof((c).begin()) ii=(c).begin();ii!=(c).end();ii++)
#define ff first
#define ss second
#define my_little_dodge 46
#define debug(x)  cerr<< #x <<" = "<< x<<endl;
using namespace std;
 
typedef long long ll;
typedef pair<int,int> PII;
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
const int N=2509;
char arr[N][N];
int up[N][N],down[N][N],ans[N];
int main(){
	int n,m;
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++)
		for(int j=1;j<=m;j++)
			scanf(" %c",&arr[i][j]);
	int h=n,w=m;		
	for(int i=1;i<=n;i++){
		int cnt=0;
		for(int j=1;j<=m;j++){
			if(arr[i][j]=='1')
				cnt++;
			else{
				if(cnt)
					w=min(w,cnt);
				cnt=0;
			}
		}
		if(cnt)
			w=min(w,cnt);
	}
	for(int j=1;j<=m;j++){
		int cnt=0;
		for(int i=1;i<=n;i++){
			if(arr[i][j]=='1')
				cnt++;
			else{
				if(cnt)
					h=min(h,cnt);
				cnt=0;	
			}	
		}
		if(cnt)
			h=min(h,cnt);
	}
	for(int j=1;j<=m;j++){
		for(int i=1;i<=n;i++)
			if(arr[i][j]=='1')
				up[i][j]=up[i-1][j]+1;
		for(int i=n;i>=1;i--)
			if(arr[i][j]=='1')
				down[i][j]=down[i+1][j]+1;	
	}
	for(int i=1;i<=w;i++)	
		ans[i]=h;	
	for(int i=1;i<=n;i++){
		int cnt=0,a=INF,b=INF;
		for(int j=1;j<=m;j++){
			if(arr[i][j]=='1'){
				umin(a,up[i][j]);
				umin(b,down[i][j]);
				umin(ans[++cnt],a+b-1);
			}
			else
				cnt=0,a=b=INF;
		}
		a=b=INF;cnt=0;
		for(int j=m;j>=1;j--){
			if(arr[i][j]=='1'){
				umin(a,up[i][j]);
				umin(b,down[i][j]);
				umin(ans[++cnt],a+b-1);
			}
			else
				cnt=0,a=b=INF;
		}
	}	
	int res=ans[1];
	for(int i=2;i<=w;i++){
		umin(ans[i],ans[i-1]);
		umax(res,i*ans[i]);
	}printf("%d\n",res);
	return 0;
}

Compilation message (stderr)

bomb.cpp: In function 'int main()':
bomb.cpp:25:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   25 |  scanf("%d%d",&n,&m);
      |  ~~~~~^~~~~~~~~~~~~~
bomb.cpp:28:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   28 |    scanf(" %c",&arr[i][j]);
      |    ~~~~~^~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100