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var DetectSquares = function () { | ||
this.ptsCount = {}; | ||
this.pts = []; | ||
}; | ||
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/** | ||
* @param {number[]} point | ||
* @return {void} | ||
/* | ||
* Time O(N) | Space O(N) | ||
* https://leetcode.com/problems/detect-squares | ||
*/ | ||
DetectSquares.prototype.add = function (point) { | ||
var str = point[0] + ',' + point[1]; | ||
if (!this.ptsCount[str]) { | ||
this.ptsCount[str] = 0; | ||
class DetectSquares { | ||
constructor () { | ||
this.map = {}; /* Space O(N) */ | ||
this.points = [];/* Space O(N) */ | ||
} | ||
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add (point, { map, points } = this) { | ||
const [ x, y ] = point; | ||
const key = this.getKey(x, y); | ||
const value = ((map[key] || 0) + 1); | ||
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this.ptsCount[str]++; | ||
this.pts.push(point); | ||
}; | ||
map[key] = value; /* Space O(N) */ | ||
points.push(point);/* Space O(N) */ | ||
} | ||
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/** | ||
* @param {number[]} point | ||
* @return {number} | ||
*/ | ||
DetectSquares.prototype.count = function (point) { | ||
var res = 0; | ||
var [x, y] = point; | ||
for (var [px, py] of this.pts) { | ||
if (Math.abs(px - x) !== Math.abs(py - y) || x === px || y === py) { | ||
continue; | ||
count (point, { points } = this, score = 0) { | ||
const [ x1, y1 ] = point; | ||
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for (const [ x2, y2 ] of points) {/* Time O(N) */ | ||
const isSame = (Math.abs(x2 - x1) === Math.abs(y2 - y1)); | ||
const isEqual = ((x1 === x2) || (y1 === y2)); | ||
const canSkip = (!isSame || isEqual); | ||
if (canSkip) continue; | ||
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score += this.getScore(x1, y1, x2, y2); | ||
} | ||
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res += (this.ptsCount[[x, py]] || 0) * (this.ptsCount[[px, y]] || 0); | ||
return score; | ||
}; | ||
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getKey (x, y) { | ||
return `${x},${y}`; | ||
} | ||
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return res; | ||
getScore (x1, y1, x2, y2, { map } = this) { | ||
const [ aKey, bKey ] = [ this.getKey(x1, y2), this.getKey(x2, y1) ]; | ||
const [ aScore, bScore ] = [ (map[aKey] || 0), (map[bKey] || 0) ]; | ||
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return (aScore * bScore); | ||
} | ||
}; | ||
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/** | ||
/** | ||
* Your DetectSquares object will be instantiated and called as such: | ||
* var obj = new DetectSquares() | ||
* obj.add(point) | ||
* var param_2 = obj.count(point) | ||
*/ | ||
*/ |
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function isHappy(n) { | ||
const visit = new Set(); | ||
/** | ||
* Hash Set - seen dynamic | ||
* Time O(log(N)) | Space O(log(N)) | ||
* https://leetcode.com/problems/happy-number/ | ||
* @param {number} n | ||
* @return {boolean} | ||
*/ | ||
var isHappy = (n, seen = new Set()) => { | ||
const hasCycle = () => ((n === 1) || (seen.has(n))); | ||
while (!hasCycle()) {/* Time O(log(N)) */ | ||
seen.add(n); /* Space O(log(N)) */ | ||
n = getNext(n); /* Time O(log(N)) */ | ||
} | ||
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return (n === 1); | ||
}; | ||
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var getNext = (n, sum = 0) => { | ||
while (0 < n) {/* Time O(log(N)) */ | ||
const remainder = (n % 10); | ||
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n = Math.floor((n / 10)); | ||
sum += (remainder * remainder); | ||
} | ||
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return sum; | ||
} | ||
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while (!visit.has(n)) { | ||
visit.add(n); | ||
n = sumOfSquares(n); | ||
/** | ||
* Hash Set - seen static | ||
* Time O(log(N)) | Space O(1) | ||
* https://leetcode.com/problems/happy-number/ | ||
* @param {number} n | ||
* @return {boolean} | ||
*/ | ||
var isHappy = (n) => { | ||
const cycles = [ 4, 16, 37, 58, 89, 145, 42, 20 ]; | ||
const seen = new Set(cycles);/* Time O(1) | Space O(1) */ | ||
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if (n == 1) return true; | ||
const hasCycle = () => ((n === 1) || (seen.has(n))); | ||
while (!hasCycle()) { /* Time O(log(N)) | Space O(1) */ | ||
n = getNext(n); | ||
} | ||
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return false; | ||
return n === 1; | ||
} | ||
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function sumOfSquares(n) { | ||
let output = 0; | ||
var getNext = (n, sum = 0) => { | ||
while (0 < n) {/* Time O(log(N)) */ | ||
const remainder = (n % 10); | ||
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n = Math.floor((n / 10)); | ||
sum += (remainder * remainder); | ||
} | ||
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return sum; | ||
} | ||
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while (n) { | ||
let digit = n % 10; | ||
digit = digit ** 2; | ||
output += digit; | ||
n = Math.floor(n / 10); | ||
/** | ||
* Pointer - n === 1 || n === 4 | ||
* Time O(log(N)) | Space O(1) | ||
* https://leetcode.com/problems/happy-number/ | ||
* @param {number} n | ||
* @return {boolean} | ||
*/ | ||
var isHappy = (n) => { | ||
const hasCycle = () => ((n === 1) || (n === 4)); | ||
while (!hasCycle()) {/* Time O(log(N)) */ | ||
n = getNext(n); /* Time O(log(N)) */ | ||
} | ||
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return output; | ||
return n === 1; | ||
} | ||
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var getNext = (n, sum = 0) => { | ||
while (0 < n) {/* Time O(log(N)) */ | ||
const remainder = (n % 10); | ||
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n = Math.floor((n / 10)); | ||
sum += (remainder * remainder); | ||
} | ||
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return sum; | ||
} | ||
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/** | ||
* Slow Fast | ||
* Time O(log(N)) | Space O(1) | ||
* https://leetcode.com/problems/happy-number/ | ||
* @param {number} n | ||
* @return {boolean} | ||
*/ | ||
var isHappy = (n) => { | ||
let [ slow, fast ] = [ n, getNext(n) ]; | ||
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const hasCyle = () => ((fast === 1) || (slow === fast)); | ||
while (!hasCyle()) { /* Time O(log(N)) */ | ||
slow = getNext(slow); /* Time O(log(N)) */ | ||
fast = getNext(getNext(fast));/* Time O(log(N)) */ | ||
} | ||
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return (fast === 1); | ||
} | ||
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var getNext = (n, sum = 0) => { | ||
while (0 < n) {/* Time O(log(N)) */ | ||
const remainder = (n % 10); | ||
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n = Math.floor((n / 10)); | ||
sum += (remainder * remainder); | ||
} | ||
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return sum; | ||
} |
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/** | ||
* Matrix | ||
* Time O(N * M) | Space O(N + M) | ||
* https://leetcode.com/problems/multiply-strings/ | ||
* @param {string} num1 | ||
* @param {string} num2 | ||
* @return {string} | ||
*/ | ||
var multiply = function (num1, num2) { | ||
if (num1 === '0' || num2 === '0') { | ||
return '0'; | ||
} | ||
var multiply = (num1, num2) => { | ||
const isZero = ((num1 === '0') || (num2 === '0')); | ||
if (isZero) return '0'; | ||
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const buffer = initBuffer(num1, num2);/* | Space (N + M) */ | ||
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multiplication(num1, num2, buffer) /* Time O(N * M) */ | ||
removeLeadingZero(buffer); /* Time O(N + M) | Time O(N + M)*/ | ||
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return buffer.join(''); /* Time O(N + M) | Space O(N + M) */ | ||
}; | ||
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var res = new Array(num1.length + num2.length).fill(0); | ||
var revNum1 = [...num1].reverse(); | ||
var revNum2 = [...num2].reverse(); | ||
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for (var i1 in revNum1) { | ||
for (var i2 in revNum2) { | ||
var digit = revNum1[i1] * revNum2[i2]; | ||
var index = Number(i1) + Number(i2); | ||
res[index] += digit; | ||
res[index + 1] += Math.floor(res[index] / 10); | ||
res[index] = res[index] % 10; | ||
var initBuffer = (num1, num2) => { | ||
const size = (num1.length + num2.length); | ||
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return new Array(size).fill(0);/* Space (N + M) */ | ||
} | ||
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var multiplication = (num1, num2, buffer) => { | ||
for (let i = (num1.length - 1); (0 <= i); i--) {/* Time O(N) */ | ||
for (let j = (num2.length - 1); (0 <= j); j--) {/* Time O(M) */ | ||
update(num1, i, num2, j, buffer); /* Space O(N + M) */ | ||
} | ||
} | ||
} | ||
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if (res[res.length - 1] === 0) { | ||
res.pop(); | ||
} | ||
var removeLeadingZero = (buffer) => { | ||
const isLeadZero = (buffer[0] === 0); | ||
if (!isLeadZero) return; | ||
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buffer.shift();/* Time O(N + M) | Time O(N + M) */ | ||
} | ||
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var update = (num1, i, num2, j, buffer) => { | ||
const curPos = (i + j); | ||
const prevPos = curPos + 1; | ||
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return res.reverse().join(''); | ||
const carry = buffer[prevPos]; | ||
const product = getProduct(num1, i, num2, j); | ||
const sum = (carry + product); | ||
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const remainder = (sum % 10); | ||
const value = ((sum - remainder) / 10); | ||
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buffer[prevPos] = remainder;/* Space O(N + M) */ | ||
buffer[curPos] += value; /* Space O(N + M) */ | ||
} | ||
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var getProduct = (num1, i, num2, j) => { | ||
const [ iNum, jNum ] = [ Number(num1[i]), Number(num2[j]) ]; | ||
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return (iNum * jNum); | ||
} | ||
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/** | ||
* Matrix | ||
* Time O(N * M) | Space O(N + M) | ||
* https://leetcode.com/problems/multiply-strings/ | ||
* @param {string} num1 | ||
* @param {string} num2 | ||
* @return {string} | ||
*/ | ||
var multiply = (num1, num2) => { | ||
const isZero = ((num1 === '0') || (num2 === '0')); | ||
if (isZero) return '0'; | ||
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const buffer = initBuffer(num1, num2);/* | Space O(N + M) */ | ||
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multiplication(num1, num2, buffer); /* Time O(N * M) | Space O(N + M) */ | ||
removeLeadingZero(buffer); /* Time O(N + M) | Space O(N + M) */ | ||
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return buffer.join(''); /* Time O(N + M) | Space O(N + M) */ | ||
}; | ||
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var initBuffer = (num1, num2) => new Array(num1.length + num2.length).fill(0);/* Space O(N + M) */ | ||
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var multiplication = (num1, num2, buffer) => { | ||
[ num1, num2 ] = /* Time O(N + M) */ | ||
[ reverse(num1), reverse(num2) ]; | ||
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for (var i1 in num1) {/* Time O(N) */ | ||
for (var i2 in num2) {/* Time O(M) */ | ||
update(num1, i1, num2, i2, buffer);/* Space O(N + M) */ | ||
} | ||
} | ||
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buffer.reverse();/* Time O(N + M) */ | ||
} | ||
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const reverse = (s) => s | ||
.split('') /* Time O(K) | Space O (K) */ | ||
.reverse();/* Time O(K) */ | ||
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var update = (num1, i1, num2, i2, buffer) => { | ||
const product = num1[i1] * num2[i2]; | ||
const index = Number(i1) + Number(i2); | ||
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buffer[index] += product; /* Space O(N + M) */ | ||
buffer[(index + 1)] += Math.floor(buffer[index] / 10);/* Space O(N + M) */ | ||
buffer[index] = (buffer[index] % 10); /* Space O(N + M) */ | ||
} | ||
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var removeLeadingZero = (buffer) => { | ||
const isZero = (buffer[0] === 0); | ||
if (!isZero) return; | ||
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buffer.shift();/* Time O(N + M) | Space O(N + M) */ | ||
} |
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