How to find the biggest island in the file
I have two-dimensional array of chars called map. Map contains three types of cell: x-land, u-river, o-sea. My task is to find the biggest island. Island is landmass connected in any of eight directions - up, top right, right... and surrounded by sea cells. There is a row that contains only sea tiles and can be interpreted as sealine that sea will not cross. Rivers do not exist on islands. I already made a method to find the longest river but i got stuck on finding the biggest isle, any advices?
the answear should be 19
public static int findLargestIsland(int x, int y) {
if (x < 0 x >= columnsAmount y < 0 y >= rowsAmount map[x][y] != 'x') { return 0; }
map[x][y] = '?';
int size = 1;
size += findLargestIsland(x - 1, y); size += findLargestIsland(x + 1, y); size += findLargestIsland(x, y - 1); size += findLargestIsland(x, y + 1); size += findLargestIsland(x - 1, y - 1); size += findLargestIsland(x - 1, y + 1); size += findLargestIsland(x + 1, y - 1); size += findLargestIsland(x + 1, y + 1);
return size; }
public static int findLargestIslandInMap() { int largestIsland = 0;
for (int i = 0; i < columnsAmount; i++) { for (int j = 0; j < rowsAmount; j++) { if (map[i][j] == 'x') { int currentIslandSize = findLargestIsland(i, j); largestIsland = Math.max(largestIsland, currentIslandSize); } } }
return largestIsland; }
if (x < 0 x >= columnsAmount y < 0 y >= rowsAmount map[x][y] != 'x') { return 0; }
map[x][y] = '?';
int size = 1;
size += findLargestIsland(x - 1, y); size += findLargestIsland(x + 1, y); size += findLargestIsland(x, y - 1); size += findLargestIsland(x, y + 1); size += findLargestIsland(x - 1, y - 1); size += findLargestIsland(x - 1, y + 1); size += findLargestIsland(x + 1, y - 1); size += findLargestIsland(x + 1, y + 1);
return size; }
public static int findLargestIslandInMap() { int largestIsland = 0;
for (int i = 0; i < columnsAmount; i++) { for (int j = 0; j < rowsAmount; j++) { if (map[i][j] == 'x') { int currentIslandSize = findLargestIsland(i, j); largestIsland = Math.max(largestIsland, currentIslandSize); } } }
return largestIsland; }
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Hey @Trzech Polaków w teamie?! Please useTIP: Narrow down your issue to simple and precise questions to maximize the chance that others will reply in here./closeor theClose Postbutton above when your problem is solved. Please remember to follow the help guidelines. This post will be automatically marked as dormant after 300 minutes of inactivity.
Please format your code to make it more readable. For java, it should look like this:
can you send the original problem?
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