More algos

Author: davivc

codility/sorting/num-disc-intersects-02.py

@@ -0,0 +1,27 @@
+def solution(A):
+    intersects=0
+    n = len(A)
+
+    # Create all starts and ends
+    points = []
+    for i in range(n):
+        points.append((i-A[i], "s"))
+        points.append((A[i]+i, "e"))
+
+    # Order by second attribute (reverse is true because we need the s first)
+    points.sort(key=lambda x: x[1], reverse=True)
+    # Order by first attribute
+    points.sort(key=lambda x: x[0])
+
+    total_open=0
+    for i in points:
+        if (i[1] == "s"):
+            intersects += total_open
+            total_open += 1
+        elif(i[1] == "e"):
+            total_open -= 1
+        # print("intersects", intersects,"\t Total:",total_open)
+
+        if(intersects > 10_000_000):
+            return -1
+    return intersects

codility/sorting/num-disc-intersects.py

@@ -0,0 +1,28 @@
+# you can write to stdout for debugging purposes, e.g.
+# print("this is a debug message")
+
+def solution(A):
+    n = len(A)
+    intersects = 0
+    starts = [0]*n
+    ends = [0]*n
+
+    for i in range(len(A)):
+        s = i - A[i] if i > A[i] else 0
+        e = i + A[i] if n-1-i > A[i] else n-1
+
+        starts[s] += 1
+        ends[e] += 1
+
+    # print(starts, ends)
+    active = 0
+    for i in range(len(A)):
+        # print(i, intersects, starts[i], ends[i], active, active * starts[i], starts[i] * (starts[i] - 1) // 2)
+        intersects += active * starts[i]
+        intersects += starts[i] * (starts[i] - 1) // 2
+        if (10_000_000 < intersects):
+            return -1
+
+        active += starts[i] - ends[i]
+
+    return intersects

codility/stacks-and-queues/brackets.py

@@ -0,0 +1,16 @@
+def solution(S):
+    my_stack = []
+
+    for i in S:
+        if (len(my_stack) > 0 and
+            ((i == ")" and my_stack[-1] == "(") or
+            (i == "]" and my_stack[-1] == "[") or
+            (i == "}" and my_stack[-1] == "{"))):
+            my_stack.pop()
+        else:
+            my_stack.append(i)
+
+    if len(my_stack) == 0:
+        return 1
+    else:
+        return 0

hackerrank/problem-solving/birthday-bar-02.py

@@ -0,0 +1,51 @@
+#!/bin/python3
+
+import math
+import os
+import random
+import re
+import sys
+
+#
+# Complete the 'birthday' function below.
+#
+# The function is expected to return an INTEGER.
+# The function accepts following parameters:
+#  1. INTEGER_ARRAY s
+#  2. INTEGER d
+#  3. INTEGER m
+#
+def birthday(s, d, m):
+    if len(s) < m:
+        return 0
+    
+    range_sum = sum(s[0:m])
+    count = 1 if range_sum == d else 0
+     
+    for i in range(1, len(s)+1-m):
+        range_sum -= s[i-1]
+        range_sum += s[i+m-1]
+                
+        if range_sum == d:
+            count += 1
+             
+    return count
+
+if __name__ == '__main__':
+    fptr = open(os.environ['OUTPUT_PATH'], 'w')
+
+    n = int(input().strip())
+
+    s = list(map(int, input().rstrip().split()))
+
+    first_multiple_input = input().rstrip().split()
+
+    d = int(first_multiple_input[0])
+
+    m = int(first_multiple_input[1])
+
+    result = birthday(s, d, m)
+
+    fptr.write(str(result) + '\n')
+
+    fptr.close()

hackerrank/problem-solving/birthday-bar.py

@@ -0,0 +1,43 @@
+#!/bin/python3
+
+import math
+import os
+import random
+import re
+import sys
+
+#
+# Complete the 'birthday' function below.
+#
+# The function is expected to return an INTEGER.
+# The function accepts following parameters:
+#  1. INTEGER_ARRAY s
+#  2. INTEGER d
+#  3. INTEGER m
+#
+def birthday(s, d, m): # O (n*n)
+    count = 0
+    for i in range(len(s)+1-m):
+        if sum(s[i:i+m]) == d:
+            count += 1
+             
+    return count
+
+if __name__ == '__main__':
+    fptr = open(os.environ['OUTPUT_PATH'], 'w')
+
+    n = int(input().strip())
+
+    s = list(map(int, input().rstrip().split()))
+
+    first_multiple_input = input().rstrip().split()
+
+    d = int(first_multiple_input[0])
+
+    m = int(first_multiple_input[1])
+
+    result = birthday(s, d, m)
+
+    fptr.write(str(result) + '\n')
+
+    fptr.close()

hackerrank/problem-solving/counting-sort1.py

@@ -0,0 +1,38 @@
+#!/bin/python3
+
+import math
+import os
+import random
+import re
+import sys
+
+#
+# Complete the 'countingSort' function below.
+#
+# The function is expected to return an INTEGER_ARRAY.
+# The function accepts INTEGER_ARRAY arr as parameter.
+#
+
+def countingSort(arr):
+    # Write your code here
+    result = [0]*100
+    
+    for i in range(len(arr)):
+        n = arr[i]
+        result[n] += 1
+    
+    return result
+
+if __name__ == '__main__':
+    fptr = open(os.environ['OUTPUT_PATH'], 'w')
+
+    n = int(input().strip())
+
+    arr = list(map(int, input().rstrip().split()))
+
+    result = countingSort(arr)
+
+    fptr.write(' '.join(map(str, result)))
+    fptr.write('\n')
+
+    fptr.close()

hackerrank/problem-solving/diagonal-diff.py

@@ -0,0 +1,41 @@
+#!/bin/python3
+
+import math
+import os
+import random
+import re
+import sys
+
+#
+# Complete the 'diagonalDifference' function below.
+#
+# The function is expected to return an INTEGER.
+# The function accepts 2D_INTEGER_ARRAY arr as parameter.
+#
+
+def diagonalDifference(arr):
+    # Write your code here
+    sumleft = 0
+    sumright = 0
+    n = len(arr)
+    for i in range(n):
+        sumleft += arr[i][i]
+        sumright += arr[n-1-i][i]
+        
+    return abs(sumleft-sumright)
+
+if __name__ == '__main__':
+    fptr = open(os.environ['OUTPUT_PATH'], 'w')
+
+    n = int(input().strip())
+
+    arr = []
+
+    for _ in range(n):
+        arr.append(list(map(int, input().rstrip().split())))
+
+    result = diagonalDifference(arr)
+
+    fptr.write(str(result) + '\n')
+
+    fptr.close()

hackerrank/problem-solving/drawning-book-02.py

@@ -0,0 +1,32 @@
+#!/bin/python3
+
+import math
+import os
+import random
+import re
+import sys
+
+#
+# Complete the 'pageCount' function below.
+#
+# The function is expected to return an INTEGER.
+# The function accepts following parameters:
+#  1. INTEGER n
+#  2. INTEGER p
+#
+
+def pageCount(n, p):
+    return min(p//2, n//2 - p//2)
+
+if __name__ == '__main__':
+    fptr = open(os.environ['OUTPUT_PATH'], 'w')
+
+    n = int(input().strip())
+
+    p = int(input().strip())
+
+    result = pageCount(n, p)
+
+    fptr.write(str(result) + '\n')
+
+    fptr.close()

hackerrank/problem-solving/drawning-book.py

@@ -0,0 +1,42 @@
+#!/bin/python3
+
+import math
+import os
+import random
+import re
+import sys
+
+#
+# Complete the 'pageCount' function below.
+#
+# The function is expected to return an INTEGER.
+# The function accepts following parameters:
+#  1. INTEGER n
+#  2. INTEGER p
+#
+
+def pageCount(n, p):
+    # Last page
+    if p!=1 and n-p == 1 and n%2 == 0:
+        return 1
+    
+    if p==1 and n-p == 1:
+        return 0
+    
+    
+    if (n-p)//2 < p//2:
+        return (n-p)//2
+    return p//2
+
+if __name__ == '__main__':
+    fptr = open(os.environ['OUTPUT_PATH'], 'w')
+
+    n = int(input().strip())
+
+    p = int(input().strip())
+
+    result = pageCount(n, p)
+
+    fptr.write(str(result) + '\n')
+
+    fptr.close()

hackerrank/problem-solving/pangrams.py

@@ -0,0 +1,38 @@
+#!/bin/python3
+
+import math
+import os
+import random
+import re
+import sys
+
+#
+# Complete the 'pangrams' function below.
+#
+# The function is expected to return a STRING.
+# The function accepts STRING s as parameter.
+#
+
+def pangrams(s):
+    # Write your code here
+    s_arr = [*s.lower().replace(' ','')]
+    s_set = set(s_arr)
+    
+    if len(s_set) == 26:
+        return 'pangram'
+        
+    return 'not pangram'
+    
+    
+    
+
+if __name__ == '__main__':
+    fptr = open(os.environ['OUTPUT_PATH'], 'w')
+
+    s = input()
+
+    result = pangrams(s)
+
+    fptr.write(result + '\n')
+
+    fptr.close()