tvl-depot/scratch/deepmind/part_two/inflight-entertainment.ts
William Carroll 0dd3987821 Solve InterviewCake's inflight-entertainment problem
Write a predicate that tests whether two films in a list of films can exactly
fill the duration of a flight.
2020-02-21 11:30:01 +00:00

85 lines
1.9 KiB
TypeScript

function canTwoMoviesFillFlightBonus(
xs: Array<number>,
duration: number
): boolean {
// Returns true if two movies exist that can fill the flight duration +/- 20
// minutes.
const seeking = {};
for (let x of xs) {
for (let i = 0; i < 40; i += 1) {
if (seeking[x + i + 1]) {
return true;
}
}
for (let i = 1; i <= 20; i += 1) {
seeking[duration - x - i] = true;
seeking[duration - x + i] = true;
}
}
return false;
}
function canTwoMoviesFillFlight(xs: Array<number>, duration: number): boolean {
const seeking = {};
for (let x of xs) {
if (seeking[x]) {
return true;
} else {
seeking[duration - x] = true;
}
}
return false;
}
// Tests
let desc = "short flight";
let actual = canTwoMoviesFillFlight([2, 4], 1);
let expected = false;
assertEquals(actual, expected, desc);
desc = "long flight";
actual = canTwoMoviesFillFlight([2, 4], 6);
expected = true;
assertEquals(actual, expected, desc);
desc = "one movie half flight length";
actual = canTwoMoviesFillFlight([3, 8], 6);
expected = false;
assertEquals(actual, expected, desc);
desc = "two movies half flight length";
actual = canTwoMoviesFillFlight([3, 8, 3], 6);
expected = true;
assertEquals(actual, expected, desc);
desc = "lots of possible pairs";
actual = canTwoMoviesFillFlight([1, 2, 3, 4, 5, 6], 7);
expected = true;
assertEquals(actual, expected, desc);
desc = "not using first movie";
actual = canTwoMoviesFillFlight([4, 3, 2], 5);
expected = true;
assertEquals(actual, expected, desc);
desc = "only one movie";
actual = canTwoMoviesFillFlight([6], 6);
expected = false;
assertEquals(actual, expected, desc);
desc = "no movies";
actual = canTwoMoviesFillFlight([], 2);
expected = false;
assertEquals(actual, expected, desc);
function assertEquals(a, b, desc) {
if (a === b) {
console.log(`${desc} ... PASS`);
} else {
console.log(`${desc} ... FAIL: ${a} != ${b}`);
}
}