Add: ans

Author: openset

problems/active-businesses/active_businesses.sql

@@ -0,0 +1 @@
+# Write your MySQL query statement below

problems/adding-two-negabinary-numbers/adding_two_negabinary_numbers.go

@@ -0,0 +1,38 @@
+package adding_two_negabinary_numbers
+
+func addNegabinary(A, B []int) []int {
+	i, j := len(A)-1, len(B)-1
+	res := make([]int, 0, i+j)
+	carry := 0
+	for i >= 0 || j >= 0 || carry != 0 {
+		if i >= 0 {
+			carry += A[i]
+			i--
+		}
+		if j >= 0 {
+			carry += B[j]
+			j--
+		}
+		res = append(res, carry&1)
+		carry = -(carry >> 1)
+	}
+
+	res = reverse(res)
+
+	// cut leading zero
+	i, end := 0, len(res)-1
+	for i < end && res[i] == 0 {
+		i++
+	}
+	return res[i:]
+}
+
+func reverse(A []int) []int {
+	i, j := 0, len(A)-1
+	for i < j {
+		A[i], A[j] = A[j], A[i]
+		i++
+		j--
+	}
+	return A
+}

problems/best-sightseeing-pair/best_sightseeing_pair.go

@@ -0,0 +1,18 @@
+package best_sightseeing_pair
+
+func maxScoreSightseeingPair(A []int) int {
+	a := A[0] // a is A[i]+i
+	res := 0
+	for j := 1; j < len(A); j++ {
+		res = max(res, a+A[j]-j)
+		a = max(a, A[j]+j)
+	}
+	return res
+}
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}

problems/binary-tree-cameras/binary_tree_cameras.go

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+package binary_tree_cameras

problems/brace-expansion-ii/brace_expansion_ii.go

@@ -0,0 +1 @@
+package brace_expansion_ii

problems/broken-calculator/broken_calculator.go

@@ -0,0 +1 @@
+package broken_calculator

problems/building-h2o/building_h2o.py

@@ -0,0 +1,17 @@
+#!/usr/bin/env python
+
+class H2O:
+    def __init__(self):
+        pass
+
+
+    def hydrogen(self, releaseHydrogen: 'Callable[[], None]') -> None:
+        
+        # releaseHydrogen() outputs "H". Do not change or remove this line.
+        releaseHydrogen()
+
+
+    def oxygen(self, releaseOxygen: 'Callable[[], None]') -> None:
+        
+        # releaseOxygen() outputs "O". Do not change or remove this line.
+        releaseOxygen()

problems/capacity-to-ship-packages-within-d-days/capacity_to_ship_packages_within_d_days.go

@@ -0,0 +1,35 @@
+package capacity_to_ship_packages_within_d_days
+
+func shipWithinDays(weights []int, D int) int {
+	lo, hi := 0, 0
+	for _, w := range weights {
+		lo = max(lo, w)
+		hi += w
+	}
+
+	for lo < hi {
+		mid := (lo + hi) >> 1
+		days, cur := 1, 0
+		for _, w := range weights {
+			if cur+w > mid {
+				days++
+				cur = 0
+			}
+			cur += w
+		}
+		if days > D {
+			lo = mid + 1
+		} else {
+			hi = mid
+		}
+	}
+
+	return lo
+}
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}

problems/car-pooling/car_pooling.go

@@ -0,0 +1,19 @@
+package car_pooling
+
+func carPooling(trips [][]int, capacity int) bool {
+	location := [1001]int{}
+	for _, t := range trips {
+		num, start, end := t[0], t[1], t[2]
+		location[start] += num
+		location[end] -= num
+	}
+
+	p := 0
+	for _, c := range location {
+		p += c
+		if p > capacity {
+			return false
+		}
+	}
+	return true
+}

problems/check-if-word-is-valid-after-substitutions/check_if_word_is_valid_after_substitutions.go

@@ -0,0 +1,27 @@
+package check_if_word_is_valid_after_substitutions
+
+func isValid(S string) bool {
+	bs := []byte(S)
+	stack := make([]byte, len(S))
+	top := -1
+
+	for _, b := range bs {
+		top++
+		stack[top] = b
+		switch top {
+		case 0:
+			if b != 'a' {
+				return false
+			}
+		case 1:
+		default:
+			if b == 'c' &&
+				stack[top-1] == 'b' &&
+				stack[top-2] == 'a' {
+				top -= 3
+			}
+		}
+	}
+
+	return top == -1
+}

problems/clone-graph/clone_graph.py

@@ -0,0 +1,12 @@
+#!/usr/bin/env python
+
+"""
+# Definition for a Node.
+class Node:
+    def __init__(self, val, neighbors):
+        self.val = val
+        self.neighbors = neighbors
+"""
+class Solution:
+    def cloneGraph(self, node: 'Node') -> 'Node':
+        

problems/clumsy-factorial/clumsy_factorial.go

@@ -0,0 +1,22 @@
+package clumsy_factorial
+
+var answers = []int{0, 1, 2, 6, 7}
+
+func clumsy(N int) int {
+	if N <= 4 {
+		return answers[N]
+	}
+	a := N*(N-1)/(N-2) + (N - 3)
+	b := (N - 4) * max(1, N-5) / max(1, N-6)
+	return a - 2*b + clumsy(N-4)
+}
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+// go to look O(1) solution
+// https://leetcode.com/problems/clumsy-factorial/discuss/252279/You-never-think-of-this-amazing-O(1)-solution

problems/coloring-a-border/coloring_a_border.go

@@ -0,0 +1,52 @@
+package coloring_a_border
+
+var dx = []int{0, 0, 1, -1}
+var dy = []int{1, -1, 0, 0}
+
+func colorBorder(grid [][]int, x0 int, y0 int, color int) [][]int {
+	m, n := len(grid), len(grid[0])
+	c := grid[x0][y0]
+
+	isBorder := func(x, y int) bool {
+		return x == 0 || x == m-1 ||
+			y == 0 || y == n-1 ||
+			grid[x][y-1] != c ||
+			grid[x][y+1] != c ||
+			grid[x-1][y] != c ||
+			grid[x+1][y] != c
+	}
+
+	connected := make([][2]int, 1, 1024)
+	hasSeen := [51][51]bool{}
+
+	connected[0] = [2]int{x0, y0}
+	hasSeen[x0][y0] = true
+
+	borders := make([][2]int, 0, 1024)
+	for len(connected) > 0 {
+		size := len(connected)
+		for i := 0; i < size; i++ {
+			p := connected[i]
+			if isBorder(p[0], p[1]) {
+				borders = append(borders, p)
+			}
+			for k := 0; k < 4; k++ {
+				x, y := p[0]+dx[k], p[1]+dy[k]
+				if 0 <= x && x < m &&
+					0 <= y && y < n &&
+					grid[x][y] == c &&
+					!hasSeen[x][y] {
+					connected = append(connected, [2]int{x, y})
+					hasSeen[x][y] = true
+				}
+			}
+		}
+		connected = connected[size:]
+	}
+
+	for _, b := range borders {
+		grid[b[0]][b[1]] = color
+	}
+
+	return grid
+}

problems/construct-quad-tree/construct_quad_tree.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python
+
+"""
+# Definition for a QuadTree node.
+class Node:
+    def __init__(self, val, isLeaf, topLeft, topRight, bottomLeft, bottomRight):
+        self.val = val
+        self.isLeaf = isLeaf
+        self.topLeft = topLeft
+        self.topRight = topRight
+        self.bottomLeft = bottomLeft
+        self.bottomRight = bottomRight
+"""
+class Solution:
+    def construct(self, grid: List[List[int]]) -> 'Node':
+        

problems/convert-to-base-2/convert_to_base_2.go

@@ -0,0 +1,39 @@
+package convert_to_base_2
+
+func baseNeg2(N int) string {
+	if N == 0 {
+		return "0"
+	}
+
+	B := make([]byte, 0, 30)
+	for N > 0 {
+		switch N & 3 {
+		case 0, 1:
+			B = append(B, byte(N&1)+'0', '0')
+		default: // 2,3
+			B = append(B, byte(N&1)+'0', '1')
+			N += 4
+			// 2^(2n)-2^(2n-1) == 2^(2n-1)
+			// 所以，把 N 转换成二进制后，每在奇数位上看见 1 就在其左边的偶数位上加 1
+			// 就可以转换成以 -2 为基的二进制了
+		}
+		N >>= 2
+	}
+
+	swap(B)
+
+	if B[0] == '0' { // no lead 0 except for N is 0
+		B = B[1:]
+	}
+
+	return string(B)
+}
+
+func swap(B []byte) {
+	i, j := 0, len(B)-1
+	for i < j {
+		B[i], B[j] = B[j], B[i]
+		i++
+		j--
+	}
+}

problems/copy-list-with-random-pointer/copy_list_with_random_pointer.py

@@ -0,0 +1,13 @@
+#!/usr/bin/env python
+
+"""
+# Definition for a Node.
+class Node:
+    def __init__(self, val, next, random):
+        self.val = val
+        self.next = next
+        self.random = random
+"""
+class Solution:
+    def copyRandomList(self, head: 'Node') -> 'Node':
+        

problems/corporate-flight-bookings/corporate_flight_bookings.go

@@ -0,0 +1 @@
+package corporate_flight_bookings

problems/count-student-number-in-departments/count_student_number_in_departments.sql

@@ -0,0 +1 @@
+# Write your MySQL query statement below

problems/customer-placing-the-largest-number-of-orders/customer_placing_the_largest_number_of_orders.sql

@@ -0,0 +1 @@
+# Write your MySQL query statement below

problems/customers-who-never-order/customers_who_never_order.sql

@@ -0,0 +1 @@
+# Write your MySQL query statement below

problems/delete-duplicate-emails/delete_duplicate_emails.sql

@@ -0,0 +1 @@
+# Write your MySQL query statement below

problems/delete-nodes-and-return-forest/delete_nodes_and_return_forest.go

@@ -0,0 +1 @@
+package delete_nodes_and_return_forest

problems/department-highest-salary/department_highest_salary.sql

@@ -0,0 +1 @@
+# Write your MySQL query statement below

problems/department-top-three-salaries/department_top_three_salaries.sql

@@ -0,0 +1 @@
+# Write your MySQL query statement below

problems/distribute-candies-to-people/distribute_candies_to_people.go

@@ -0,0 +1 @@
+package distribute_candies_to_people

problems/distribute-coins-in-binary-tree/distribute_coins_in_binary_tree.go

@@ -0,0 +1 @@
+package distribute_coins_in_binary_tree

problems/duplicate-zeros/duplicate_zeros.go

@@ -0,0 +1,29 @@
+package duplicate_zeros
+
+func duplicateZeros(A []int) {
+	n := len(A)
+	//
+	count := 0
+	for i := 0; i < n; i++ {
+		if A[i] == 0 {
+			count++
+		}
+	}
+	// copy A[i] to A[j]
+	copy := func(i, j int) {
+		if j < n {
+			A[j] = A[i]
+		}
+	}
+	//
+	i, j := n-1, n+count-1
+	for i < j {
+		copy(i, j)
+		if A[i] == 0 {
+			j--
+			copy(i, j)
+		}
+		i--
+		j--
+	}
+}

problems/employee-bonus/employee_bonus.sql

@@ -0,0 +1 @@
+# Write your MySQL query statement below