# 11 - largest product in a grid

In the 20×20 grid below, four numbers along a diagonal line have been marked in red.

The product of these numbers is 26 × 63 × 78 × 14 = 1788696.

What is the greatest product of four adjacent numbers in the same direction (up, down, left, right, or diagonally) in the 20×20 grid?

cevap : 70600674

``````// euler_project_11.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <string.h>

// function prototypes
void copy_raw_data_2_matrix(unsigned char hor_index, unsigned char ver_index);
unsigned int scan_horizontal();
unsigned int scan_vertical();
unsigned int scan_right_diagonal();
unsigned int scan_left_diagonal();

// global veriables
unsigned char matrix_data[20][20];
unsigned char raw_data[] =  {8,02,22,97,38,15,00,40,00,75,04,05,07,78,52,12,50,77,91,8,
49,49,99,40,17,81,18,57,60,87,17,40,98,43,69,48,04,56,62,00,
81,49,31,73,55,79,14,29,93,71,40,67,53,88,30,03,49,13,36,65,
52,70,95,23,04,60,11,42,69,24,68,56,01,32,56,71,37,02,36,91,
22,31,16,71,51,67,63,89,41,92,36,54,22,40,40,28,66,33,13,80,
24,47,32,60,99,03,45,02,44,75,33,53,78,36,84,20,35,17,12,50,
32,98,81,28,64,23,67,10,26,38,40,67,59,54,70,66,18,38,64,70,
67,26,20,68,02,62,12,20,95,63,94,39,63,8,40,91,66,49,94,21,
24,55,58,05,66,73,99,26,97,17,78,78,96,83,14,88,34,89,63,72,
21,36,23,9,75,00,76,44,20,45,35,14,00,61,33,97,34,31,33,95,
78,17,53,28,22,75,31,67,15,94,03,80,04,62,16,14,9,53,56,92,
16,39,05,42,96,35,31,47,55,58,88,24,00,17,54,24,36,29,85,57,
86,56,00,48,35,71,89,07,05,44,44,37,44,60,21,58,51,54,17,58,
19,80,81,68,05,94,47,69,28,73,92,13,86,52,17,77,04,89,55,40,
04,52,8,83,97,35,99,16,07,97,57,32,16,26,26,79,33,27,98,66,
88,36,68,87,57,62,20,72,03,46,33,67,46,55,12,32,63,93,53,69,
04,42,16,73,38,25,39,11,24,94,72,18,8,46,29,32,40,62,76,36,
20,69,36,41,72,30,23,88,34,62,99,69,82,67,59,85,74,04,36,16,
20,73,35,29,78,31,90,01,74,31,49,71,48,86,81,16,23,57,05,54,
01,70,54,71,83,51,54,69,16,92,33,48,61,43,52,01,89,19,67,48};

int _tmain(int argc, _TCHAR* argv[]) {

unsigned int hor_index = 0;
unsigned int ver_index = 0;
unsigned int max_hor = 0;
unsigned int max_ver = 0;
unsigned int max_right_diagonal = 0;
unsigned int max_left_diagonal = 0;
unsigned int max_array[4] = {0};
unsigned int max = 0;
unsigned char i;

memset(matrix_data, 0, sizeof(matrix_data[0][0]) * 20 * 20);

copy_raw_data_2_matrix(hor_index, ver_index);

max_hor = scan_horizontal();
max_ver = scan_vertical();
max_right_diagonal = scan_right_diagonal();
max_left_diagonal = scan_left_diagonal();

max_array[0] = max_hor;
max_array[1] = max_ver;
max_array[2] = max_right_diagonal;
max_array[3] = max_left_diagonal;

for(i=0; i<4; i++){
if(max_array[i] > max_array[i+1]){
max = max_array[i];
}
}

printf("sonuc = %d",max);

return 0;
}

unsigned int scan_left_diagonal() {

unsigned char i,j;
unsigned int multiply[2] = {0};
unsigned int big_one = 0;

for(i=0; i<17; i++) {
for (j=0; j<17; j++) {
multiply[j%2] = matrix_data[i][j] * matrix_data[i+1][j+1] * matrix_data[i+2][j+2] * matrix_data[i+3][j+3];

if (multiply[0] > big_one) {
big_one = multiply[0];
} else if (multiply[1] > big_one) {
big_one = multiply[1];
}
}
}

return big_one;
}

unsigned int scan_right_diagonal() {

unsigned char i,j;
unsigned int multiply[2] = {0};
unsigned int big_one = 0;

for(i=0; i<17; i++) {
for (j=0; j<17; j++) {
multiply[j%2] = matrix_data[i+3][j] * matrix_data[i+2][j+1] * mat-rix_data[i+1][j+2] * matrix_data[i][j+3];

if (multiply[0] > big_one) {
big_one = multiply[0];
} else if (multiply[1] > big_one) {
big_one = multiply[1];
}
}
}

return big_one;
}

unsigned int scan_vertical() {

unsigned char i,j;
unsigned int multiply[2] = {0};
unsigned int big_one = 0;

for(j=0; j<20; j++) {
for (i=0; i<17; i++) {
multiply[i%2] = matrix_data[i][j] * matrix_data[i+1][j] * matrix_data[i+2][j] * matrix_data[i+3][j];

if (multiply[0] > big_one) {
big_one = multiply[0];
} else if (multiply[1] > big_one) {
big_one = multiply[1];
}
}
}

return big_one;
}

unsigned int scan_horizontal() {

unsigned char i,j;
unsigned int multiply[2] = {0};
unsigned int temp[2] = {0};
unsigned int big_one = 0;

for(i=0; i<20; i++) {
for (j=0; j<17; j++) {
multiply[j%2] = matrix_data[i][j] * matrix_data[i][j+1] * matrix_data[i][j+2] * matrix_data[i][j+3];

if (multiply[0] > big_one) {
big_one = multiply[0];
} else if (multiply[1] > big_one) {
big_one = multiply[1];
}
}
}

return big_one;
}

void copy_raw_data_2_matrix(unsigned char hor_index, unsigned char ver_index){

unsigned int i = 0;

for (hor_index=0; hor_index<20; hor_index++) {
for (ver_index=0; ver_index<20; ver_index++) {
matrix_data[hor_index][ver_index] = raw_data[i];
i++;
}
}
}
``````