add certificate: add final certificate & solutions

Author: waldohidalgo

Check Difference.py

@@ -0,0 +1,7 @@
+def f1():
+    x+=1
+    print(x)
+
+x=12
+f1()
+print("x")

README.md

@@ -1,6 +1,6 @@
 # 21-Day Coding Challenge: Ninja Slayground 2.0
 
-Repositorio con el código solución a los desafíos diarios.
+Repositorio con el código solución a los 21 desafíos diarios.
 
 ## Tabla de Contenido
 
@@ -10,6 +10,7 @@ Repositorio con el código solución a los desafíos diarios.
     - [Certificado Participación](#certificado-participación)
     - [Certificado Level 1: 7 days Streak](#certificado-level-1-7-days-streak)
     - [Certificado Level 2: 14 days Streak](#certificado-level-2-14-days-streak)
+    - [Certificado Level 3: 21 days Streak](#certificado-level-3-21-days-streak)
   - [Ejercicios Resueltos](#ejercicios-resueltos)
     - [Day 1: Switch Case statement](#day-1-switch-case-statement)
     - [Day 2: Nth Fibonacci Number](#day-2-nth-fibonacci-number)
@@ -26,6 +27,12 @@ Repositorio con el código solución a los desafíos diarios.
     - [Day 13: Binary Search](#day-13-binary-search)
     - [Day 14: Sort An Array of 0s, 1s and 2s](#day-14-sort-an-array-of-0s-1s-and-2s)
     - [Day 15: Implement Lower Bound](#day-15-implement-lower-bound)
+    - [Day 16: Valid Parentheses](#day-16-valid-parentheses)
+    - [Day 17: Implement Upper Bound](#day-17-implement-upper-bound)
+    - [Day 18: Spiral Matrix](#day-18-spiral-matrix)
+    - [Day 19: Zero Matrix](#day-19-zero-matrix)
+    - [Day 20: Pascal's Triangle](#day-20-pascals-triangle)
+    - [Day 21: Number of Inversions](#day-21-number-of-inversions)
 
 ## Certificados Obtenidos
 
@@ -41,6 +48,10 @@ Repositorio con el código solución a los desafíos diarios.
 
 ![Certificado Level 2: 14 days Streak](./certificados/certificado_level2.webp)
 
+### Certificado Level 3: 21 days Streak
+
+![Certificado Level 3: 21 days Streak](./certificados/certificado_level3.webp)
+
 ## Ejercicios Resueltos
 
 ### Day 1: Switch Case statement
@@ -417,3 +428,223 @@ def lowerBound(arr: [int], n: int, x: int) -> int:
             l=mid+1
     return l
 ```
+
+### Day 16: Valid Parentheses
+
+You're given a string 'S' consisting of "{", "}", "(", ")", "[" and "]" .
+
+Return true if the given string 'S' is balanced, else return false.
+
+For example:
+'S' = "{}()".
+
+There is always an opening brace before a closing brace i.e. '{' before '}', '(' before ').
+So the 'S' is Balanced.
+
+```py
+def isValidParenthesis(s: str) -> bool:
+    # Write your code here
+    stack=[]
+    for c in s:
+        if c=='(' or c=='[' or c=='{':
+            stack.append(c)
+        elif c==')':
+            if stack and stack[-1]=='(':
+                stack.pop()
+            else:
+                return False
+        elif c==']':
+            if stack and stack[-1]=='[':
+                stack.pop()
+            else:
+                return False
+        elif c=='}':
+            if stack and stack[-1]=='{':
+                stack.pop()
+            else:
+                return False
+    return not stack
+```
+
+### Day 17: Implement Upper Bound
+
+You are given a sorted array ‘arr’ containing ‘n’ integers and an integer ‘x’.Implement the ‘upper bound’ function to find the index of the upper bound of 'x' in the array.
+
+Note:
+
+1. The upper bound in a sorted array is the index of the first value that is greater than a given value.
+2. If the greater value does not exist then the answer is 'n', Where 'n' is the size of the array.
+3. Try to write a solution that runs in log(n) time complexity.
+
+Example:
+
+Input : ‘arr’ = {2,4,6,7} and ‘x’ = 5,
+
+Output: 2
+
+Explanation: The upper bound of 5 is 6 in the given array, which is at index 2 (0-indexed).
+
+```py
+from typing import List
+
+def upperBound(arr: List[int], x: int, n: int) -> int:
+    # Write your code here.
+    l,r=0,n-1
+    while l<=r:
+        mid=(l+r)//2
+        if arr[mid]==x and (arr[mid+1]>x if mid<n-1 else True):
+            return mid+1
+        elif arr[mid]>x:
+            r=mid-1
+        else:
+            l=mid+1
+    return l
+```
+
+### Day 18: Spiral Matrix
+
+You are given a 2D matrix ‘MATRIX’ of ‘N’\*’M’ dimension. You have to return the spiral traversal of the matrix.
+
+Example:
+
+Input:
+MATRIX = [ [1, 3, 5, 7], [10, 11, 16, 20], [23, 30, 34, 60] ]
+Output:
+1 3 5 7 20 60 34 30 23 10 11 16
+
+Explanation: Starting from the element in the first row and the first column, traverse from left to right (1 3 5 7), then top to bottom (20 60), then right to left (34 30 23), then bottom to up (10) and then left to right (11 16).
+
+```py
+def spiralMatrix(matrix : List[List[int]]) -> List[int]:
+    # Write your code here.
+    i,j=0,0
+    directions=[(0,1),(1,0),(0,-1),(-1,0)]
+    directionIndex=0
+    m,n=len(matrix),len(matrix[0])
+    arr=[n,m]
+    res=[]
+    while all(arr):
+        for r in range(2):
+            for c in range(arr[r]):
+                res.append(matrix[i][j])
+                if c<arr[r]-1:
+                    i,j=i+directions[directionIndex][0],j+directions[directionIndex][1]
+                else:
+                    directionIndex=(directionIndex+1)%4
+                    i,j=i+directions[directionIndex][0],j+directions[directionIndex][1]
+            arr[(r+1)%2]-=1
+    return res
+```
+
+### Day 19: Zero Matrix
+
+You are given a matrix 'MATRIX' of dimension 'N' x 'M'. Your task is to make all the elements of row 'i' and column 'j' equal to 0 if any element in the ith row or jth column of the matrix is 0.
+
+Note:
+
+1. The number of rows should be at least 1.
+
+2. The number of columns should be at least 1.
+
+```py
+def zeroMatrix(matrix, n, m):
+    # Write your code here.
+    if n<=1 or m<=1:
+        return matrix
+
+    first_row_have_zero=any(matrix[0][j]==0 for j in range(m))
+    first_col_have_zero=any(matrix[i][0]==0 for i in range(n))
+
+    for i in range(1,n):
+        for j in range(1,m):
+            if matrix[i][j]==0:
+                matrix[0][j]=0
+                matrix[i][0]=0
+    for i in range(1,n):
+        for j in range(1,m):
+            if matrix[0][j]==0 or matrix[i][0]==0:
+                matrix[i][j]=0
+    if first_row_have_zero:
+        for j in range(m):
+            matrix[0][j]=0
+    if first_col_have_zero:
+        for i in range(n):
+            matrix[i][0]=0
+```
+
+### Day 20: Pascal's Triangle
+
+You are given an integer N. Your task is to return a 2-D ArrayList containing the pascal’s triangle till the row N.
+
+A Pascal's triangle is a triangular array constructed by summing adjacent elements in preceding rows. Pascal's triangle contains the values of the binomial coefficient.
+
+```py
+def printPascal(n:int):
+    # Write your code here.
+    # Return a list of lists.
+    res=[[1]]
+    for i in range(1,n):
+        res.append([1]+[res[i-1][j]+res[i-1][j-1] for j in range(1,i)]+[1])
+    return res
+```
+
+### Day 21: Number of Inversions
+
+There is an integer array ‘A’ of size ‘N’.
+
+Number of inversions in an array can be defined as the number of pairs of ‘i’, ‘j’ such that ‘i’ < ‘j’ and ‘A[i]’ > ‘A[j]’.
+
+You must return the number of inversions in the array.
+
+For example,
+Input:
+A = [5, 3, 2, 1, 4], N = 5
+Output:
+7
+Explanation:
+The pairs satisfying the condition for inversion are (1, 2), (1, 3), (1, 4), (1, 5), (2, 3), (2, 4), and (3, 4).
+The number of inversions in the array is 7.
+
+```py
+from typing import *
+
+class Solution:
+    def mergeSort(self,arr,low,high):
+        count_inversion=0
+        if low<high:
+            mid=(low+high)//2
+            count_inversion+=self.mergeSort(arr,low,mid)
+            count_inversion+=self.mergeSort(arr,mid+1,high)
+            count_inversion+=self.merge(arr,low,mid,high)
+        return count_inversion
+    def merge(self,arr,low,mid,high):
+        count_inversion=0
+        temp=[0]*(high-low+1)
+        i=low
+        j=mid+1
+        k=0
+        while i<=mid and j<=high:
+            if arr[i]<=arr[j]:
+                temp[k]=arr[i]
+                k+=1
+                i+=1
+            else:
+                temp[k]=arr[j]
+                k+=1
+                j+=1
+                count_inversion+=mid-i+1 #se agrega la inversion
+        while i<=mid:
+            temp[k]=arr[i]
+            k+=1
+            i+=1
+        while j<=high:
+            temp[k]=arr[j]
+            k+=1
+            j+=1
+        for i in range(low,high+1):
+            arr[i]=temp[i-low]
+        return count_inversion
+def numberOfInversions(a : List[int], n : int) -> int:
+    # Write your code here.
+    return Solution().mergeSort(a,0,n-1)
+```

certificados/certificado_level3.webp

@@ -0,0 +1,25 @@
+def isValidParenthesis(s: str) -> bool:
+    # Write your code here
+    stack=[]
+    for c in s:
+        if c=='(' or c=='[' or c=='{':
+            stack.append(c)
+        elif c==')':
+            if stack and stack[-1]=='(':
+                stack.pop()
+            else:
+                return False
+        elif c==']':
+            if stack and stack[-1]=='[':
+                stack.pop()
+            else:
+                return False
+        elif c=='}':
+            if stack and stack[-1]=='{':
+                stack.pop()
+            else:
+                return False
+    return not stack
+
+s="[[}["
+print(isValidParenthesis(s))

day16/Valid Parentheses.py

@@ -0,0 +1,23 @@
+from typing import List
+
+def upperBound(arr: List[int], x: int, n: int) -> int:
+    # Write your code here.
+    l,r=0,n-1
+    while l<=r:
+        mid=(l+r)//2
+        if arr[mid]==x and (arr[mid+1]>x if mid<n-1 else True):
+            return mid+1
+        elif arr[mid]>x:
+            r=mid-1
+        else:
+            l=mid+1
+    return l
+
+#arr=[1,5,5,7,7,9,10]
+#x=5
+# arr=[1,2,5,6,10]
+# x=10
+arr=[1,4,7,8,10]
+x=7
+n=len(arr)
+print(upperBound(arr,x,n))