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Improve solution for problem 11

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This commit is contained in:
daniele 2019-09-22 20:54:27 +02:00
parent 29dce902bb
commit 95611e4401
Signed by: fuxino
GPG Key ID: 6FE25B4A3EE16FDA
2 changed files with 67 additions and 128 deletions
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129
C/p011.c
View File

@ -1,3 +1,30 @@
/* n the 20×20 grid below, four numbers along a diagonal line have been marked in red.
*
* 08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08
* 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 08 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 09 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 09 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 08 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 08 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
*
* 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?*/
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
@ -30,64 +57,39 @@ int main(int argc, char **argv)
clock_gettime(CLOCK_MONOTONIC, &start);
for(i = 0; i < 20; i++)
/* Brute-force approach: for each number in the grid, try products with its three
* adjacent numbers in every direction (horizontal, vertical and the two diagonals).
* If the product is larger than the current maximum, save it.*/
for(i = 0; i < 17; i++)
{
for(j = 0; j < 20; j++)
for(j = 0; j < 17; j++)
{
prod = 1;
for(k = j; k < j + 4 && k < 20; k++)
/* Horizontal direction.*/
for(k = j; k < j + 4; k++)
{
prod *= grid[i][k];
}
if(k == j + 4)
if(prod > max)
{
if(prod > max)
{
max = prod;
}
max = prod;
}
prod = 1;
for(k = j; k > j - 4 && k >= 0; k--)
{
prod *= grid[i][k];
}
if(k == j - 4)
{
if(prod > max)
{
max = prod;
}
}
prod = 1;
for(k = i; k < i + 4 && k < 20; k++)
/* Vertical direction.*/
for(k = i; k < i + 4; k++)
{
prod *= grid[k][j];
}
if(k == i + 4)
if(prod > max)
{
if(prod > max)
{
max = prod;
}
max = prod;
}
prod = 1;
for(k = i; k > i - 4 && k >= 0; k--)
{
prod *= grid[k][j];
}
if(k == i - 4)
{
if(prod > max)
{
max = prod;
}
}
prod = 1;
for(k = i, w = j; k < i + 4 && w < j + 4 && k < 20 && w < 20; k++, w++)
/* Diagonal direction, from top left to bottom right.*/
for(k = i, w = j; k < i + 4 && w < j + 4; k++, w++)
{
prod *= grid[k][w];
}
@ -98,44 +100,23 @@ int main(int argc, char **argv)
max = prod;
}
}
}
}
/* The last diagonal is handled separately.*/
for(i = 0; i < 17; i++)
{
for(j = 3; j < 20; j++)
{
prod = 1;
for(k = i, w = j; k < i + 4 && w > j - 4 && k < 20 && w >= 0; k++, w--)
/* Diagonal direction, from top right to bottom left.*/
for(k = i, w = j; k < i + 4 && w > j - 4; k++, w--)
{
prod *= grid[k][w];
}
if(k == i + 4 && w == j - 4)
if(prod > max)
{
if(prod > max)
{
max = prod;
}
}
prod = 1;
for(k = i, w = j; k > i - 4 && w < j + 4 && k >= 0 && w < 20; k--, w++)
{
prod *= grid[k][w];
}
if(k == i - 4 && w == j + 4)
{
if(prod > max)
{
max = prod;
}
}
prod = 1;
for(k = i, w = j; k > i - 4 && w > j - 4 && k >= 0 && w >= 0; k--, w--)
{
prod *= grid[k][w];
}
if(k == i - 4 && w == j - 4)
{
if(prod > max)
{
max = prod;
}
max = prod;
}
}
}

66
Python/p011.py
View File

@ -28,94 +28,52 @@ def main():
max_ = 0
for i in range(20):
for j in range(20):
for i in range(17):
for j in range(17):
prod = 1
k = j
while k < j + 4 and k < 20:
while k < j + 4:
prod = prod * grid[i][k]
k = k + 1
if k == j + 4 and prod > max_:
max_ = prod
prod = 1
k = j
while k > j - 4 and k >= 0:
prod = prod * grid[i][k]
k = k - 1
if k == j - 4 and prod > max_:
if prod > max_:
max_ = prod
prod = 1
k = i
while k < i + 4 and k < 20:
while k < i + 4:
prod = prod * grid[k][j]
k = k + 1
if k == i + 4 and prod > max_:
max_ = prod
prod = 1
k = i
while k > i - 4 and k >= 0:
prod = prod * grid[k][j]
k = k - 1
if k == i - 4 and prod > max_:
if prod > max_:
max_ = prod
prod = 1
k = i
w = j
while k < i + 4 and w < j + 4 and k < 20 and w < 20:
while k < i + 4 and w < j + 4:
prod = prod * grid[k][w]
k = k + 1
w = w + 1
if k == i + 4 and w == j + 4 and prod > max_:
if prod > max_:
max_ = prod
for i in range(17):
for j in range(3, 20):
prod = 1
k = i
w = j
while k < i + 4 and w > j - 4 and k < 20 and w >= 0:
while k < i + 4 and w > j - 4:
prod = prod * grid[k][w]
k = k + 1
w = w - 1
if k == i + 4 and w == j - 4 and prod > max_:
max_ = prod
prod = 1
k = i
w = j
while k > i - 4 and w < j + 4 and k >= 0 and w < 20:
prod = prod * grid[k][w]
k = k - 1
w = w + 1
if k == i - 4 and w == j + 4 and prod > max_:
max_ = prod
prod = 1
k = i
w = j
while k > i - 4 and w > j - 4 and k >= 0 and w >= 0:
prod = prod * grid[k][w]
k = k - 1
w = w - 1
if k == i - 4 and w == j - 4 and prod > max_:
if prod > max_:
max_ = prod
end = default_timer()