euler11.c


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46

#include <stdio.h>
#define MAX 20

int grid[MAX][MAX];
int biggest[MAX][MAX];

int main()
{
	int i,j,M=0;
	for (i=0;i<MAX;++i){
		for (j=0;j<MAX;++j){
			scanf("%d",&grid[i][j]);
		}
	}
	for (i=0;i<MAX;++i){
		for (j=0;j<MAX;++j){
			int p;
			biggest[i][j]=0;
			if (i<MAX-3){
				p = grid[i][j]*grid[i+1][j]*grid[i+2][j]*grid[i+3][j];
			}
			if (j<MAX-3){
				p = grid[i][j]*grid[i][j+1]*grid[i][j+2]*grid[i][j+3];
				if (p>biggest[i][j])
					biggest[i][j]=p;
				if (i<MAX-3){
					p = grid[i][j]*grid[i+1][j+1]*
						grid[i+2][j+2]*grid[i+3][j+3];
					if (p>biggest[i][j])
						biggest[i][j]=p;
				}
				if (i>=3){
					p = grid[i][j]*grid[i-1][j+1]*
						grid[i-2][j+2]*grid[i-3][j+3];
					if (p>biggest[i][j])
						biggest[i][j]=p;
				}
			}
			if (biggest[i][j]>M)
				M=biggest[i][j];
		}
	}
	printf("%d\n",M);
	return 0;
}