2.5 KiB
2.5 KiB
title | id | challengeType |
---|---|---|
Zig-zag matrix | 594810f028c0303b75339ad8 | 5 |
Description
0 1 5 6 14 2 4 7 13 15 3 8 12 16 21 9 11 17 20 22 10 18 19 23 24Write a function that takes the size of the zig-zag matrix, and returns the corresponding matrix as two-dimensional array.
Instructions
Tests
tests:
- text: ZigZagMatrix must be a function
testString: assert.equal(typeof ZigZagMatrix, 'function', 'ZigZagMatrix must be a function');
- text: ZigZagMatrix should return array
testString: assert.equal(typeof ZigZagMatrix(1), 'object', 'ZigZagMatrix should return array');
- text: ZigZagMatrix should return an array of nestes arrays
testString: assert.equal(typeof ZigZagMatrix(1)[0], 'object', 'ZigZagMatrix should return an array of nestes arrays');
- text: ZigZagMatrix(1) should return [[0]]
testString: assert.deepEqual(ZigZagMatrix(1), zm1, 'ZigZagMatrix(1) should return [[0]]');
- text: ZigZagMatrix(2) should return [[0, 1], [2, 3]]
testString: assert.deepEqual(ZigZagMatrix(2), zm2, 'ZigZagMatrix(2) should return [[0, 1], [2, 3]]');
- text: ZigZagMatrix(5) must return specified matrix
testString: assert.deepEqual(ZigZagMatrix(5), zm5, 'ZigZagMatrix(5) must return specified matrix');
Challenge Seed
function ZigZagMatrix(n) {
// Good luck!
return [[], []];
}
After Test
const zm1 = [[0]];
const zm2 = [[0, 1], [2, 3]];
const zm5 = [
[0, 1, 5, 6, 14],
[2, 4, 7, 13, 15],
[3, 8, 12, 16, 21],
[9, 11, 17, 20, 22],
[10, 18, 19, 23, 24]
];
Solution
function ZigZagMatrix(n) {
const mtx = [];
for (let i = 0; i < n; i++) {
mtx[i] = [];
}
let i = 1;
let j = 1;
for (let e = 0; e < n * n; e++) {
mtx[i - 1][j - 1] = e;
if ((i + j) % 2 === 0) {
// Even stripes
if (j < n) j++;
else i += 2;
if (i > 1) i--;
} else {
// Odd stripes
if (i < n) i++;
else j += 2;
if (j > 1) j--;
}
}
return mtx;
}