feat: Solved 15 Leetcode problems

Author: ralvarezdev

monthly/2024-july/easy/water-bottles.js

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+/**
+ * @param {number} numBottles
+ * @param {number} numExchange
+ * @return {number}
+ */
+var numWaterBottles = function(numBottles, numExchange) {
+    let maxWaterBottles=numBottles;
+
+    while((numBottles-=numExchange)>=0){
+        maxWaterBottles++
+        numBottles++
+    }
+
+    return maxWaterBottles
+};

random/2024-july/easy/find-the-index-of-the-first-occurrence-in-a-string.js

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+/**
+ * @param {string} haystack
+ * @param {string} needle
+ * @return {number}
+ */
+var strStr = function(haystack, needle) {
+    return haystack.indexOf(needle)
+};

monthly/2024-july/easy/longest-substring-without-repeating-characters.js renamed to random/2024-july/easy/longest-substring-without-repeating-characters.js

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+/**
+ * @param {number[]} nums
+ * @return {number[]}
+ */
+var numberGame = function(nums) {
+    nums.sort((a,b)=>a-b)
+
+        for(let i=0, temp;i<nums.length;i+=2)
+{
+    temp=nums[i]
+    nums[i]=nums[i+1]
+    nums[i+1]=temp
+}
+
+return nums
+}

random/2024-july/easy/minimum-number-game.js

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+
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var romanToInt = function(s) {
+    const conv={
+        'I':1,
+        'V':5,
+        'X':10,
+        'L':50,
+        'C':100,
+        'D':500,
+        'M':1000
+    }
+
+    let total=0
+
+    for(let i=0, next, c;i<s.length;i++){
+        next=(i<s.length-1)?s[i+1]:null
+        c=s[i]
+
+        if(c==='I')
+            total+=(next!==null&&(next==='V'||next==='X'))?-1:1
+        else if(c==='X')
+            total+=(next!==null&&(next==='L'||next==='C'))?-10:10
+        else if(c==='C')
+            total+=(next!==null&&(next==='D'||next==='M'))?-100:100
+        else
+            total+=conv[c]
+    }
+    return total
+};

monthly/2024-july/easy/remove-duplicates-from-sorted-array.js renamed to random/2024-july/easy/remove-duplicates-from-sorted-array.js

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+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number}
+ */
+var searchInsert = function(nums, target) {
+    let low=0,high= nums.length-1,mid, isUpper
+
+    while(high>=low)
+    {
+        mid= Math.floor((high+low)/2)
+
+        if(nums[mid]===target)
+            return mid
+
+        else if(nums[mid]>target){
+            high=mid-1
+            isUpper=false
+        }
+
+        else{
+           low=mid+1
+           isUpper=true
+        }
+    }
+
+    return isUpper?mid+1:mid
+};

monthly/2024-july/easy/remove-element.js renamed to random/2024-july/easy/remove-element.js

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+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number[]}
+ */
+var twoSum = function(nums, target) {
+    const map =new Map()
+
+    nums.forEach((num, i)=>{
+        const val = map.get(num)
+
+        if(val===undefined)
+            map.set(num, [i])
+        else
+        {
+            val.push(i)
+            map.set(num, val)
+        }
+    })
+
+    for(let i=0;i<nums.length;i++){
+        const diff=target-nums[i]
+        const idxs=  map.get(diff)
+
+        if(idxs===undefined)
+            continue
+
+        if(diff===nums[i]){
+            if(idxs.length<2)
+                continue
+            return idxs.slice(0,2)
+        }
+
+        return [i, idxs[0]]
+    }
+};

random/2024-july/easy/roman-to-integer.js

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+/**
+ * @param {string} s
+ * @return {number}
+ */
+var calculate = function(s) {
+    s=s.replace(' ','')
+    let length =s.length,isPlusSign=false
+
+    const getLastNumberIdx=()=>{
+        let idx
+
+        for(let i=length-1;i>=0;i--)
+            if(i===0)
+                idx=0
+            else if(s[i]==='+'||s[i]==='-'||s[i]==='*'||s[i]==='/')
+            {
+                idx=i+1
+                break
+            }
+
+        let n = s.substring(idx, length)
+        length=idx
+        return n
+    }
+
+    const numbers=[], operators=[]
+    let accum,n, prevOp=null, currOp=null
+
+    const hasGreaterPrecedence=(prevOp, currOp)=>{
+        if(currOp==='/'||prevOp===null)
+            return true
+
+        return currOp!=='+'
+    }
+
+    const checkSign=(n)=>{
+        if(length===0||s[length-1]!=='-')
+            return n
+
+        length--
+        isPlusSign=true
+        return -n
+    }
+
+    const peekCurrSign=()=>isPlusSign?'+':s[length-1]
+
+    const getCurrSign=()=>{
+        const sign = peekCurrSign()
+
+        if(!isPlusSign)
+            length--
+        else
+            isPlusSign=false
+
+        return sign
+    }
+
+    accum=getLastNumberIdx()
+    if(accum===null)
+        return null
+
+    accum=checkSign(parseInt(accum))
+    numbers.push(accum)
+
+    while(length>0)
+    {
+        prevOp=null
+
+        while(length>0&&hasGreaterPrecedence(prevOp, peekCurrSign()))
+        {
+            currOp=getCurrSign()
+            operators.push(currOp)
+
+            n=getLastNumberIdx()
+            if(n===null)
+                return null
+
+            n=checkSign(parseInt(n))
+            numbers.push(n)
+
+            prevOp=currOp
+        }
+
+        accum=numbers.pop()
+
+        while(operators.length>0){
+            // Testing
+            //console.log(`[${numbers}] [${operators}] [${accum}] [${s}]`)
+
+            n = numbers.pop()
+            currOp=operators.pop()
+
+            if(currOp==='+')
+                accum+=n
+
+            else if(currOp==='-')
+                accum-=n
+            else if(currOp==='*')
+                accum*=n
+
+            else if(currOp==='/')
+                accum=Math.trunc(accum/n)
+        }
+        numbers.push(accum)
+    }
+
+    return accum
+};

random/2024-july/easy/search-insert-position.js

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+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var largestPerimeter = function(nums) {
+    let longestSize, perimeter
+
+    nums.sort((a,b)=>a-b)
+
+    while(nums.length>=3){
+        longestSide = nums.pop()
+        perimeter = nums.reduce((accum, value)=>accum+value)
+
+        if(perimeter>longestSide)
+            return perimeter+longestSide
+    }
+    return -1
+};

random/2024-july/easy/two-sums.js

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+/**
+ * @param {number[]} nums
+ * @return {number[][]}
+ */
+var threeSum = function(nums) {
+    nums.sort((a,b)=>a-b)
+
+    if(nums[0]>0||nums.length<2)
+        return []
+
+    const triplets=[], idxsMap =new Map(),tripletsMap = new Map()
+    let val
+
+    nums.forEach((num, i)=>{
+        val = idxsMap.get(num)
+
+        if(val===undefined)
+            idxsMap.set(num, [i])
+        else
+        {
+            val.push(i)
+            idxsMap.set(num, val)
+        }
+    })
+
+    for(let i=0, j, innerMap, diff, isValid;i<nums.length&&nums[i]<=0;i++)
+        for(j=i+1;j<nums.length;j++){
+            diff=0-nums[i]-nums[j]
+
+            if(diff<nums[i]||diff<nums[j])
+                break
+
+            val = idxsMap.get(diff)
+
+            if(val!==undefined){
+                if(tripletsMap.get(nums[i])===undefined)
+                    tripletsMap.set(nums[i], new Map())
+                innerMap=tripletsMap.get(nums[i])
+
+                if(innerMap.get(nums[j])===undefined)
+                   innerMap.set(nums[j], new Map())
+                innerMap=innerMap.get(nums[j])
+
+                if(innerMap.get(diff)!==undefined)
+                    continue
+
+                for(let k of val){
+                    isValid = k!==i&&k!==j
+
+                    if(isValid){
+                        triplets.push([nums[i], nums[j], diff])
+                        break
+                    }
+                }
+                innerMap.set(diff, isValid)
+            }
+        }
+
+    return triplets
+};

monthly/2024-july/medium/add-two-numbers.js renamed to random/2024-july/medium/add-two-numbers.js

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+# Write your MySQL query statement below
+SELECT a1.machine_id, ROUND(AVG(a1.avg_activity_time),3) AS processing_time FROM (SELECT a1.machine_id, a1.process_id, MAX(a1.timestamp)-MIN(a1.timestamp) AS avg_activity_time FROM Activity AS a1 GROUP BY a1.machine_id, a1.process_id) AS a1 GROUP BY a1.machine_id;

random/2024-july/medium/basic-calculator-ii.js

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+# Write your MySQL query statement below
+SELECT v.customer_id AS customer_id, COUNT(v.visit_id) AS count_no_trans FROM Visits AS v LEFT JOIN Transactions AS t ON v.visit_id = t.visit_id WHERE t.transaction_id IS NULL GROUP BY v.customer_id;

monthly/2024-july/medium/divide-two-integers.js renamed to random/2024-july/medium/divide-two-integers.js

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+# Write your MySQL query statement below
+SELECT e.name, b.bonus FROM Employee AS e LEFT JOIN Bonus AS b ON b.empId=e.empId WHERE b.bonus IS NULL OR b.bonus<1000;

random/2024-july/medium/find-polygon-with-the-largest-perimeter.js

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+# Write your MySQL query statement below
+SELECT p.product_name, s.year, s.price FROM Sales AS s INNER JOIN Product AS p ON s.product_id=p.product_id;

random/2024-july/medium/three-sum.js

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+# Write your MySQL query statement below
+SELECT w2.id FROM (SELECT w1.id AS id, w1.recordDate AS second_recordDate,w1.temperature AS second_temperature,LAG(w1.recordDate) OVER (ORDER BY w1.recordDate) AS first_recordDate ,LAG(w1.temperature) OVER (ORDER BY w1.recordDate) AS first_temperature FROM Weather AS w1) AS w2 WHERE w2.second_temperature IS NOT NULL AND DATE_ADD(w2.second_recordDate, INTERVAL -1 DAY) = w2.first_recordDate  AND w2.second_temperature>w2.first_temperature  ORDER BY w2.id;

top-sql-50/basic-joins/easy/average-time-of-process-per-machine.sql

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+-- Write your PostgreSQL query statement below
+SELECT st.student_id, st.student_name, su.subject_name, COUNT(ex.subject_name) AS attended_exams FROM Students AS st CROSS JOIN Subjects AS su LEFT JOIN Examinations AS ex ON st.student_id = ex.student_id AND su.subject_name=ex.subject_name GROUP BY st.student_id, st.student_name,su.subject_name,ex.subject_name ORDER BY st.student_id, su.subject_name;