2843767_mle.cpp

北大大牛代码 1240道题的原代码 超级权威

#include <stdio.h>
#include <string.h>
#define MAX 371

int n;
short a[MAX][MAX];
short row[MAX][MAX][MAX], col[MAX][MAX][MAX];
int ansi, ansj;

int min(int a,int b)
{
	return a<b?a:b;
}

int main()
{
	int i, j, k, cnt, max, tmp;

	scanf("%d",&n);
	for(i = 0; i < n; i++)
		for(j = 0; j < n; j++)
			scanf("%d",&a[i][j]);
	for(i = 0; i < n; i++)
		for(j = 0; j < n; j++)
		{
			cnt = 0;
			for(k = n-1; k >= 0; k--)
			{
				if(a[i][k]==a[j][k])
					cnt++;
				else
					cnt = 0;
				col[i][j][k] = cnt;
			}
		}
	for(i = 0; i < n; i++)
		for(j = 0; j < n; j++)
		{
			cnt = 0;
			for(k = n-1; k >= 0; k--)
			{
				if(a[k][i]==a[k][j])
					cnt++;
				else
					cnt = 0;
				row[i][j][k] = cnt;
			}
		}
	max = 0;ansi = ansj = -1;
	for(i = 0; i < n; i++)
		for(j = 0; j < n; j++)
			for(k = min(n-i,n-j); k > max; k--)
			{
				if(col[i][i+k-1][j]>=k&&row[j][j+k-1][i]>=k)
				{
					tmp = min(k,min(col[i][i+k-1][j],row[j][j+k-1][i]));
					if(tmp>max)
					{
						max = tmp;
						ansi = i;
						ansj = j;
						break;
					}
				}
			}
	printf("%d %d %d\n",ansi+1,ansj+1,max);
	return 0;
}