ProjectEuler/c/src/0011.c

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>

#define IMP
#include "primes.h"
#include "da.h"

#define ROWS 20
#define COLS 20

struct point4 {
	uint16_t i1;
	uint16_t i2;
	uint16_t i3;
	uint16_t i4;
};


int
main(int argc, const char **argv)
{
	uint64_t grid[ROWS * COLS] = {
		 8,  2, 22, 97, 38, 15,  0, 40,  0, 75,  4,  5,  7, 78, 52, 12,
		50, 77, 91,  8, 49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40,
		98, 43, 69, 48,  4, 56, 62,  0, 81, 49, 31, 73, 55, 79, 14, 29,
		93, 71, 40, 67, 53, 88, 30,  3, 49, 13, 36, 65, 52, 70, 95, 23,
		 4, 60, 11, 42, 69, 24, 68, 56,  1, 32, 56, 71, 37,  2, 36, 91,
		22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28,
		66, 33, 13, 80, 24, 47, 32, 60, 99,  3, 45,  2, 44, 75, 33, 53,
		78, 36, 84, 20, 35, 17, 12, 50, 32, 98, 81, 28, 64, 23, 67, 10,
		26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70, 67, 26, 20, 68,
		 2, 62, 12, 20, 95, 63, 94, 39, 63,  8, 40, 91, 66, 49, 94, 21,
		24, 55, 58,  5, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88,
		34, 89, 63, 72, 21, 36, 23,  9, 75,  0, 76, 44, 20, 45, 35, 14,
		 0, 61, 33, 97, 34, 31, 33, 95, 78, 17, 53, 28, 22, 75, 31, 67,
		15, 94,  3, 80,  4, 62, 16, 14,  9, 53, 56, 92, 16, 39,  5, 42,
		96, 35, 31, 47, 55, 58, 88, 24,  0, 17, 54, 24, 36, 29, 85, 57,
		86, 56,  0, 48, 35, 71, 89,  7,  5, 44, 44, 37, 44, 60, 21, 58,
		51, 54, 17, 58, 19, 80, 81, 68,  5, 94, 47, 69, 28, 73, 92, 13,
		86, 52, 17, 77,  4, 89, 55, 40,  4, 52,  8, 83, 97, 35, 99, 16,
		 7, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66, 88, 36, 68, 87,
		57, 62, 20, 72,  3, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69,
		 4, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18,  8, 46, 29, 32,
		40, 62, 76, 36, 20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69,
		82, 67, 59, 85, 74,  4, 36, 16, 20, 73, 35, 29, 78, 31, 90,  1,
		74, 31, 49, 71, 48, 86, 81, 16, 23, 57,  5, 54,  1, 70, 54, 71,
		83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52,  1, 89, 19, 67, 48,
	};
	uint64_t res = 0;
	uint64_t i = 0, j = 0;
	uint64_t sum = 0;

#define T(i, j) ((j)+((i)*ROWS))
	for ( i = 3 ; i < ROWS - 4; ++i ) {
		for ( j = 3 ; j < COLS - 4; ++j ) {
			sum = grid[T(i, j)]
				* grid[T(i-1, j-1)]
				* grid[T(i-2, j-2)]
				* grid[T(i-3, j-3)];
			if ( sum > res ) {
				res = sum;
			}
			sum = grid[T(i, j)]
				* grid[T(i-1, j+1)]
				* grid[T(i-2, j+2)]
				* grid[T(i-3, j+3)];
			if ( sum > res ) {
				res = sum;
			}
			sum = grid[T(i, j)]
				* grid[T(i+1, j+1)]
				* grid[T(i+2, j+2)]
				* grid[T(i+3, j+3)];
			if ( sum > res ) {
				res = sum;
			}
			sum = grid[T(i, j)]
				* grid[T(i+1, j-1)]
				* grid[T(i+2, j-2)]
				* grid[T(i+3, j-3)];
			if ( sum > res ) {
				res = sum;
			}


			sum = grid[T(i, j)]
				* grid[T(i, j-1)]
				* grid[T(i, j-2)]
				* grid[T(i, j-3)];
			if ( sum > res ) {
				res = sum;
			}
			sum = grid[T(i, j)]
				* grid[T(i-1, j)]
				* grid[T(i-2, j)]
				* grid[T(i-3, j)];
			if ( sum > res ) {
				res = sum;
			}
			sum = grid[T(i, j)]
				* grid[T(i, j+1)]
				* grid[T(i, j+2)]
				* grid[T(i, j+3)];
			if ( sum > res ) {
				res = sum;
			}
			sum = grid[T(i, j)]
				* grid[T(i+1, j)]
				* grid[T(i+2, j)]
				* grid[T(i+3, j)];
			if ( sum > res ) {
				res = sum;
			}
		}
	}

	printf("Result = %ld!\n", res);

	(void) argc; (void) argv;
	return 0;
}