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Add number of islands

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Kayla
2020-10-01 21:50:05 -04:00
parent e3ee2b2675
commit b06aa8733f
1 changed files with 21 additions and 20 deletions
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41
Graphs/NumberOfIslands.js
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@ -1,4 +1,5 @@
/* Number of Islands
https://dev.to/rattanakchea/amazons-interview-question-count-island-21h6
Given a 2d grid map of '1's (land) and '0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by water.
two a dimensial grid map
@ -49,37 +50,37 @@ const grid = [
['1', '1', '0', '0', '0'],
['1', '1', '0', '0', '0'],
['0', '0', '1', '0', '0'],
['0', '0', '0', '1', '1'],
];
['0', '0', '0', '1', '1']
]
const islands = (matrixGrid) => {
const matrix = matrixGrid;
let counter = 0;
const matrix = matrixGrid
let counter = 0
const flood = (row, col) => {
if (row < 0 || col < 0) return; // Off the map above or left
if (row >= matrix.length || col >= matrix[row].length) return; // Off the map below or right
if (row < 0 || col < 0) return // Off the map above or left
if (row >= matrix.length || col >= matrix[row].length) return // Off the map below or right
const tile = matrix[row][col];
if (tile !== '1') return;
const tile = matrix[row][col]
if (tile !== '1') return
matrix[row][col] = '0';
matrix[row][col] = '0'
flood(row + 1, col); // Down
flood(row - 1, col); // Up
flood(row, col + 1); // Right
flood(row, col - 1); // Left
};
flood(row + 1, col) // Down
flood(row - 1, col) // Up
flood(row, col + 1) // Right
flood(row, col - 1) // Left
}
for (let row = 0; row < matrix.length; row += 1) {
for (let col = 0; col < matrix[row].length; col += 1) {
const current = matrix[row][col];
const current = matrix[row][col]
if (current === '1') {
flood(row, col);
counter += 1;
flood(row, col)
counter += 1
}
}
}
return counter;
};
return counter
}
console.log(islands(grid))