2.4 KiB
2.4 KiB
title | id | challengeType |
---|---|---|
Identity matrix | 5a23c84252665b21eecc7eb1 | 5 |
Description
Instructions
Tests
tests:
- text: <code>idMatrix</code> should be a function.
testString: assert(typeof idMatrix=='function','<code>idMatrix</code> should be a function.');
- text: <code>idMatrix(1)</code> should return an array.
testString: assert(Array.isArray(idMatrix(1)),'<code>idMatrix(1)</code> should return an array.');
- text: <code>idMatrix(1)</code> should return <code>'+JSON.stringify(results[0])+'</code>.
testString: assert.deepEqual(idMatrix(1),results[0],'<code>idMatrix(1)</code> should return <code>'+JSON.stringify(results[0])+'</code>.');
- text: <code>idMatrix(2)</code> should return <code>'+JSON.stringify(results[1])+'</code>.
testString: assert.deepEqual(idMatrix(2),results[1],'<code>idMatrix(2)</code> should return <code>'+JSON.stringify(results[1])+'</code>.');
- text: <code>idMatrix(3)</code> should return <code>'+JSON.stringify(results[2])+'</code>.
testString: assert.deepEqual(idMatrix(3),results[2],'<code>idMatrix(3)</code> should return <code>'+JSON.stringify(results[2])+'</code>.');
- text: <code>idMatrix(4)</code> should return <code>'+JSON.stringify(results[3])+'</code>.
testString: assert.deepEqual(idMatrix(4),results[3],'<code>idMatrix(4)</code> should return <code>'+JSON.stringify(results[3])+'</code>.');
Challenge Seed
function idMatrix (n) {
// Good luck!
}
After Test
let results=[[ [ 1 ] ],
[ [ 1, 0 ], [ 0, 1 ] ],
[ [ 1, 0, 0 ], [ 0, 1, 0 ], [ 0, 0, 1 ] ],
[ [ 1, 0, 0, 0 ], [ 0, 1, 0, 0 ], [ 0, 0, 1, 0 ], [ 0, 0, 0, 1 ] ]]
Solution
function idMatrix (n) {
return Array.apply(null, new Array(n)).map(function (x, i, xs) {
return xs.map(function (_, k) {
return i === k ? 1 : 0;
})
});
}