[Project Euler] Problem 011

(Java)

package q001_q025;
 
public class Problem011 {
    private static int[][] SQUARE = {
            { 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},
        };
    public static void main(String[] args) {
        int max = -1;
        int temp = 0;
        
        //y = c
        for(int i = 0; i < SQUARE.length; ++i) {
            for(int j = 0; j < (SQUARE.length - 3); ++j) {
                temp = SQUARE[i][j] * SQUARE[i][j + 1] * SQUARE[i][j + 2] * SQUARE[i][j + 3];
                
                if(temp > max) {
                    max = temp;
                }
            }
        }
        //x = c
        for(int i = 0; i < SQUARE.length; ++i) {
            for(int j = 0; j < (SQUARE.length - 3); ++j) {
                temp = SQUARE[j][i] * SQUARE[j + 1][i] * SQUARE[j + 2][i] * SQUARE[j + 3][i]; 
                
                if(temp > max) {
                    max = temp;
                }
            }
        }
        
        //y = -x
        for(int i = 0; i <= 16; ++i) {
            for(int j = 0; j <= 16; ++j) {
                temp = SQUARE[i][j] * SQUARE[i + 1][j + 1] * SQUARE[i + 2][j + 2] * SQUARE[i + 3][j + 3];
                
                if(temp > max) {
                    max = temp;
                }
            }
        }
        
        //y = x
        for(int i = 19; i >= 3; --i) {
            for(int j = 0; j <= 16; ++j) {
                temp = SQUARE[i][j] * SQUARE[i - 1][j + 1] * SQUARE[i - 2][j + 2] * SQUARE[i - 3][j + 3];
                
                if(temp > max) {
                    max = temp;
                }
            }
        }
 
        System.out.println(max);
 
    }
}
 

정답: 70600674

단순하게 풀었다. 주어진 숫자들을 2차원 배열에 저장한 후 그냥 쭉 훑었다.