more math

.vscode/settings.json

@@ -46,7 +46,8 @@
         "ratio": "cpp",
         "tuple": "cpp",
         "string.h": "c",
-        "locale": "cpp"
+        "locale": "cpp",
+        "numeric": "cpp"
     },
     "files.exclude": {
         "**/.git": true,

README.md

@@ -1,6 +1,6 @@
 # [![HackerRank](https://hrcdn.net/hackerrank/assets/brand/h_mark_sm-30dc0e0cbd2dded63b294819ff853a90.svg)](https://www.hackerrank.com) HackerRank
 
-[![Build Status](https://travis-ci.org/rene-d/hackerrank.svg?branch=master)](https://travis-ci.org/rene-d/hackerrank) [![641 solutions and counting](https://img.shields.io/badge/Challenges-641-blue.svg)](https://www.hackerrank.com/rene_d?hr_r=1)
+[![Build Status](https://travis-ci.org/rene-d/hackerrank.svg?branch=master)](https://travis-ci.org/rene-d/hackerrank) [![649 solutions and counting](https://img.shields.io/badge/Challenges-649-blue.svg)](https://www.hackerrank.com/rene_d?hr_r=1)
 
 [HackerRank](https://www.hackerrank.com/dashboard) is a great place to learn, improve, play with your programming skills.
 

algorithms/CMakeLists.txt

@@ -7,3 +7,4 @@ add_subdirectory(search)
 add_subdirectory(dynamic-programming)
 add_subdirectory(bit-manipulation)
 add_subdirectory(game-theory)
+add_subdirectory(algo-debugging)

algorithms/README.md

@@ -182,3 +182,10 @@ Name | Preview | Code | Difficulty
 ---- | ------- | ---- | ----------
 [Game of Stones](https://www.hackerrank.com/challenges/game-of-stones-1)|A Game of Stones|[Python](game-theory/game-of-stones-1.py)|Easy
 
+#### [Debugging](https://www.hackerrank.com/domains/algorithms/algo-debugging)
+
+Name | Preview | Code | Difficulty
+---- | ------- | ---- | ----------
+[Prime Dates](https://www.hackerrank.com/challenges/prime-date)|Find the number of prime dates in a range|[C++](algo-debugging/prime-date.cpp) [Python](algo-debugging/prime-date.py)|Medium
+[Zig Zag Sequence](https://www.hackerrank.com/challenges/zig-zag-sequence)|Find a zig zag sequence of the given array.|[C++](algo-debugging/zig-zag-sequence.cpp) [Python](algo-debugging/zig-zag-sequence.py)|Medium
+

algorithms/algo-debugging/CMakeLists.txt

@@ -0,0 +1,6 @@
+add_hackerrank(prime-date prime-date.cpp)
+add_hackerrank_py(prime-date.py)
+
+dirty_cpp(prime-date)
+add_hackerrank_py(zig-zag-sequence.py)
+add_hackerrank(zig-zag-sequence zig-zag-sequence.cpp)

algorithms/algo-debugging/README.md

@@ -0,0 +1,13 @@
+
+### [Algorithms](https://www.hackerrank.com/domains/algorithms)
+The true test of problem solving: when one realizes that time and memory aren't infinite.
+
+
+
+#### [Debugging](https://www.hackerrank.com/domains/algorithms/algo-debugging)
+
+Name | Preview | Code | Difficulty
+---- | ------- | ---- | ----------
+[Prime Dates](https://www.hackerrank.com/challenges/prime-date)|Find the number of prime dates in a range|[C++](prime-date.cpp) [Python](prime-date.py)|Medium
+[Zig Zag Sequence](https://www.hackerrank.com/challenges/zig-zag-sequence)|Find a zig zag sequence of the given array.|[C++](zig-zag-sequence.cpp) [Python](zig-zag-sequence.py)|Medium
+

algorithms/algo-debugging/prime-date.cpp

@@ -0,0 +1,84 @@
+// Algorithms > Debugging > Prime Dates
+// Find the number of prime dates in a range
+//
+// https://www.hackerrank.com/challenges/prime-date/problem
+// challenge id: 63495
+//
+
+#include <bits/stdc++.h>
+using namespace std;
+
+int month[15];
+
+void updateLeapYear(int year) {
+    if(year % 400 == 0) {
+        month[2] = 29;
+    } else if(year % 100 == 0) {
+        month[2] = 28;
+    } else if(year % 4 == 0) {
+        month[2] = 29;
+    } else {
+        month[2] = 28;
+    }
+}
+
+void storeMonth() {
+    month[1] = 31;
+    month[2] = 28;
+    month[3] = 31;
+    month[4] = 30;
+    month[5] = 31;
+    month[6] = 30;
+    month[7] = 31;
+    month[8] = 31;
+    month[9] = 30;
+    month[10] = 31;
+    month[11] = 30;
+    month[12] = 31;
+}
+
+int findLuckyDates(int d1, int m1, int y1, int d2, int m2, int y2) {
+    storeMonth();
+
+    int result = 0;
+
+    while(true) {
+        int x = d1;
+        x = x * 100 + m1;
+        x = x * 10000 + y1;
+        if(x % 4 == 0 || x % 7 == 0) {
+            result = result + 1;
+        }
+        if(d1 == d2 && m1 == m2 && y1 == y2) {
+            break;
+        }
+        updateLeapYear(y1);
+        d1 = d1 + 1;
+        if(d1 > month[m1]) {
+            m1 = m1 + 1;
+            d1 = 1;
+            if(m1 > 12) {
+                y1 =  y1 + 1;
+                m1 = 1;
+            }
+        }
+    }
+    return result;
+}
+
+int main() {
+    string str;
+    int d1, m1, y1, d2, m2, y2;
+    getline(cin, str);
+    for(int i = 0; i < str.size(); i++) {
+        if(str[i] == '-') {
+            str[i] = ' ';
+        }
+    }
+    stringstream ss;
+    ss << str;
+    ss >> d1 >> m1 >> y1 >> d2 >> m2 >> y2;
+
+    int result = findLuckyDates(d1, m1, y1, d2, m2, y2);
+    cout << result << endl;
+}

algorithms/algo-debugging/prime-date.py

@@ -0,0 +1,70 @@
+# Algorithms > Debugging > Prime Dates
+# Find the number of prime dates in a range
+#
+# https://www.hackerrank.com/challenges/prime-date/problem
+# challenge id: 63495
+#
+
+import re
+month = []
+
+def updateLeapYear(year):
+    if year % 400 == 0:
+        month[2] = 29
+    elif year % 100 == 0:
+        month[2] = 28
+    elif year % 4 == 0:
+        month[2] = 29
+    else:
+        month[2] = 28
+
+def storeMonth():
+    month[1] = 31
+    month[2] = 28
+    month[3] = 31
+    month[4] = 30
+    month[5] = 31
+    month[6] = 30
+    month[7] = 31
+    month[8] = 31
+    month[9] = 30
+    month[10] = 31
+    month[11] = 30
+    month[12] = 31
+
+def findPrimeDates(d1, m1, y1, d2, m2, y2):
+    storeMonth()
+    result = 0
+
+    while(True):
+        x = d1
+        x = x * 100 + m1
+        x = x * 10000 + y1
+        if x % 4 == 0 or x % 7 == 0:
+            result = result + 1
+        if d1 == d2 and m1 == m2 and y1 == y2:
+            break
+        updateLeapYear(y1)
+        d1 = d1 + 1
+        if d1 > month[m1]:
+            m1 = m1 + 1
+            d1 = 1
+            if m1 > 12:
+                y1 =  y1 + 1
+                m1 = 1
+    return result;
+
+for i in range(1, 15):
+    month.append(31)
+
+line = input()
+date = re.split('-| ', line)
+d1 = int(date[0])
+m1 = int(date[1])
+y1 = int(date[2])
+d2 = int(date[3])
+m2 = int(date[4])
+y2 = int(date[5])
+
+result = findPrimeDates(d1, m1, y1, d2, m2, y2)
+print(result)

algorithms/algo-debugging/zig-zag-sequence.cpp

@@ -0,0 +1,44 @@
+// Algorithms > Debugging > Zig Zag Sequence
+// Find a zig zag sequence of the given array.
+//
+// https://www.hackerrank.com/challenges/zig-zag-sequence/problem
+// challenge id: 63282
+//
+
+#include <bits/stdc++.h>
+using namespace std;
+
+void findZigZagSequence(vector < int > a, int n){
+    sort(a.begin(), a.end());
+    int mid = (n - 1)/2;
+    swap(a[mid], a[n-1]);
+
+    int st = mid + 1;
+    int ed = n - 2;
+    while(st <= ed){
+        swap(a[st], a[ed]);
+        st = st + 1;
+        ed = ed - 1;
+    }
+    for(int i = 0; i < n; i++){
+        if(i > 0) cout << " ";
+        cout << a[i];
+    }
+    cout << endl;
+}
+
+int main() {
+    int n, x;
+    int test_cases;
+    cin >> test_cases;
+
+    for(int cs = 1; cs <= test_cases; cs++){
+        cin >> n;
+        vector < int > a;
+        for(int i = 0; i < n; i++){
+            cin >> x;
+            a.push_back(x);
+        }
+        findZigZagSequence(a, n);
+    }
+}

algorithms/algo-debugging/zig-zag-sequence.py

@@ -0,0 +1,31 @@
+# Algorithms > Debugging > Zig Zag Sequence
+# Find a zig zag sequence of the given array.
+#
+# https://www.hackerrank.com/challenges/zig-zag-sequence/problem
+# challenge id: 63282
+#
+
+def findZigZagSequence(a, n):
+    a.sort()
+    mid = int((n - 1)/2)
+    a[mid], a[n-1] = a[n-1], a[mid]
+
+    st = mid + 1
+    ed = n - 2
+    while(st <= ed):
+        a[st], a[ed] = a[ed], a[st]
+        st = st + 1
+        ed = ed - 1
+
+    for i in range (n):
+        if i == n-1:
+            print(a[i])
+        else:
+            print(a[i], end = ' ')
+    return
+
+test_cases = int(input())
+for cs in range (test_cases):
+    n = int(input())
+    a = list(map(int, input().split()))
+    findZigZagSequence(a, n)

algorithms/implementation/sherlock-and-squares.py

@@ -4,7 +4,6 @@
 # https://www.hackerrank.com/challenges/sherlock-and-squares/problem
 #
 
-
 def squares(a, b):
     # Complete this function
 
@@ -26,6 +25,7 @@ def squares(a, b):
             break
     return nb
 
+
 if __name__ == "__main__":
     q = int(input().strip())
     for a0 in range(q):

mathematics/README.md

@@ -67,21 +67,26 @@ Name | Preview | Code | Difficulty
 [Breaking Sticks](https://www.hackerrank.com/challenges/breaking-sticks)|Find the length of the longest sequence of moves.|[C++](number-theory/breaking-sticks.cpp)|Medium
 [Cheese and Random Toppings](https://www.hackerrank.com/challenges/cheese-and-random-toppings)|How many ways are there to choose exactly R toppings from N toppings?|[Python](number-theory/cheese-and-random-toppings.py)|Easy
 [Easy GCD](https://www.hackerrank.com/challenges/easy-gcd-1)|Find the maximum number less than K such that GCD of all numbers is still more than one!|[Python](number-theory/easy-gcd-1.py)|Medium
+[Satisfactory Pairs](https://www.hackerrank.com/challenges/pairs-again)|How many pairs of integers give a solution?|[C++](number-theory/pairs-again.cpp)|Hard
 [Manasa loves Maths](https://www.hackerrank.com/challenges/manasa-loves-maths)|Find out if any permutation of the given number is divisible by 8.|[Python](number-theory/manasa-loves-maths.py)|Medium
+[Largest Non-Coprime Submatrix](https://www.hackerrank.com/challenges/largest-coprime-submatrix)|Given a matrix find the largest coprime submatrix.|[C++](number-theory/largest-coprime-submatrix.cpp)|Hard
 [John and GCD list](https://www.hackerrank.com/challenges/john-and-gcd-list)|Help John in making a list from GCD list|[Python](number-theory/john-and-gcd-list.py)|Easy
 [Easy math](https://www.hackerrank.com/challenges/easy-math)|Help Johnny in figuring out the value of Y|[Python](number-theory/easy-math.py)|Medium
 [Binomial Coefficients](https://www.hackerrank.com/challenges/binomial-coefficients)|Calculate how many binomial coefficients of n become 0 after modulo by P.|[Python](number-theory/binomial-coefficients.py)|Medium
 [Lucy and Flowers](https://www.hackerrank.com/challenges/lucy-and-flowers)|Help Lucy's father with a computation involving flowers|[C++](number-theory/lucy-and-flowers.cpp)|Medium
+[nCr](https://www.hackerrank.com/challenges/ncr)|Given n and r, in how many ways can r items be chosen from n items?|[Python](number-theory/ncr.py)|Expert
 
 #### [Combinatorics](https://www.hackerrank.com/domains/mathematics/combinatorics)
 
 Name | Preview | Code | Difficulty
 ---- | ------- | ---- | ----------
-[nCr table](https://www.hackerrank.com/challenges/ncr-table)|Help Jim calculating nCr values|[Python](combinatorics/ncr-table.py)|Medium
+[nCr table](https://www.hackerrank.com/challenges/ncr-table)|Help Jim calculating nCr values|[C++](combinatorics/ncr-table.cpp) [Python](combinatorics/ncr-table.py)|Medium
 [Coinage](https://www.hackerrank.com/challenges/coinage)|Find the number of ways to pay a given amount, given a set of coins with prescribed denominations.|[Python](combinatorics/coinage.py)|Medium
 [Building a List](https://www.hackerrank.com/challenges/building-a-list)|Generate all possible combinations of a string|[Python](combinatorics/building-a-list.py)|Medium
 [Merge List](https://www.hackerrank.com/challenges/merge-list)|Help Shashank in merging two list.|[Python](combinatorics/merge-list.py)|Medium
 [A Chocolate Fiesta](https://www.hackerrank.com/challenges/a-chocolate-fiesta)|Find the number of even subsets in the given set of numbers.|[Python](combinatorics/a-chocolate-fiesta.py)|Easy
+[Sherlock and Pairs](https://www.hackerrank.com/challenges/sherlock-and-pairs)|Count the number of pairs that satisfy a given constraint.|[Python](combinatorics/sherlock-and-pairs.py)|Medium
+[Picking Cards](https://www.hackerrank.com/challenges/picking-cards)|How many ways can you pick up all the cards from a table?|[Python](combinatorics/picking-cards.py)|Easy
 
 #### [Algebra](https://www.hackerrank.com/domains/mathematics/algebra)
 
@@ -98,6 +103,7 @@ Name | Preview | Code | Difficulty
 [Number Groups](https://www.hackerrank.com/challenges/number-groups)|Find the sum of consecutive odd number groups.|[Python](algebra/number-groups.py)|Easy
 [Tell the Average](https://www.hackerrank.com/challenges/tell-the-average)|Tell me average of all list value.|[Python](algebra/tell-the-average.py)|Medium
 [Wet Shark and 42](https://www.hackerrank.com/challenges/wet-shark-and-42)|Help Wet Shark escape the gods of 42.|[Python](algebra/wet-shark-and-42.py)|Easy
+[Sherlock and Square](https://www.hackerrank.com/challenges/sherlock-and-square)|Help Sherlock in finding the total side lengths of squares.|[Python](algebra/sherlock-and-square.py)|Hard
 [Manasa and Sub-sequences ](https://www.hackerrank.com/challenges/manasa-and-sub-sequences)|Help Manasa in getting candies|[Python](algebra/manasa-and-sub-sequences.py)|Medium
 
 #### [Geometry](https://www.hackerrank.com/domains/mathematics/geometry)

mathematics/algebra/CMakeLists.txt

@@ -10,3 +10,4 @@ add_hackerrank_py(number-groups.py)
 add_hackerrank_py(shashank-and-list.py)
 add_hackerrank_py(tell-the-average.py)
 add_hackerrank_py(wet-shark-and-42.py)
+add_hackerrank_py(sherlock-and-square.py)

mathematics/algebra/README.md

@@ -18,5 +18,6 @@ Name | Preview | Code | Difficulty
 [Number Groups](https://www.hackerrank.com/challenges/number-groups)|Find the sum of consecutive odd number groups.|[Python](number-groups.py)|Easy
 [Tell the Average](https://www.hackerrank.com/challenges/tell-the-average)|Tell me average of all list value.|[Python](tell-the-average.py)|Medium
 [Wet Shark and 42](https://www.hackerrank.com/challenges/wet-shark-and-42)|Help Wet Shark escape the gods of 42.|[Python](wet-shark-and-42.py)|Easy
+[Sherlock and Square](https://www.hackerrank.com/challenges/sherlock-and-square)|Help Sherlock in finding the total side lengths of squares.|[Python](sherlock-and-square.py)|Hard
 [Manasa and Sub-sequences ](https://www.hackerrank.com/challenges/manasa-and-sub-sequences)|Help Manasa in getting candies|[Python](manasa-and-sub-sequences.py)|Medium
 

mathematics/algebra/sherlock-and-square.py

@@ -0,0 +1,13 @@
+# Mathematics > Algebra > Sherlock and Square
+# Help Sherlock in finding the total side lengths of squares.
+#
+# https://www.hackerrank.com/challenges/sherlock-and-square/problem
+# https://www.hackerrank.com/contests/w11/challenges/sherlock-and-square
+# challenge id: 4429
+#
+
+MOD = 1000000007
+
+for _ in range(int(input())):
+    n = int(input())
+    print((pow(2, n + 1, MOD) + 2) % MOD)

mathematics/combinatorics/CMakeLists.txt

@@ -3,3 +3,6 @@ add_hackerrank_py(a-chocolate-fiesta.py)
 add_hackerrank_py(ncr-table.py)
 add_hackerrank_py(building-a-list.py)
 add_hackerrank_py(coinage.py)
+add_hackerrank(ncr-table ncr-table.cpp)
+add_hackerrank_py(sherlock-and-pairs.py)
+add_hackerrank_py(picking-cards.py)

mathematics/combinatorics/README.md

@@ -7,9 +7,11 @@ Without mathematics, there's nothing you can do. Everything around you is mathem
 
 Name | Preview | Code | Difficulty
 ---- | ------- | ---- | ----------
-[nCr table](https://www.hackerrank.com/challenges/ncr-table)|Help Jim calculating nCr values|[Python](ncr-table.py)|Medium
+[nCr table](https://www.hackerrank.com/challenges/ncr-table)|Help Jim calculating nCr values|[C++](ncr-table.cpp) [Python](ncr-table.py)|Medium
 [Coinage](https://www.hackerrank.com/challenges/coinage)|Find the number of ways to pay a given amount, given a set of coins with prescribed denominations.|[Python](coinage.py)|Medium
 [Building a List](https://www.hackerrank.com/challenges/building-a-list)|Generate all possible combinations of a string|[Python](building-a-list.py)|Medium
 [Merge List](https://www.hackerrank.com/challenges/merge-list)|Help Shashank in merging two list.|[Python](merge-list.py)|Medium
 [A Chocolate Fiesta](https://www.hackerrank.com/challenges/a-chocolate-fiesta)|Find the number of even subsets in the given set of numbers.|[Python](a-chocolate-fiesta.py)|Easy
+[Sherlock and Pairs](https://www.hackerrank.com/challenges/sherlock-and-pairs)|Count the number of pairs that satisfy a given constraint.|[Python](sherlock-and-pairs.py)|Medium
+[Picking Cards](https://www.hackerrank.com/challenges/picking-cards)|How many ways can you pick up all the cards from a table?|[Python](picking-cards.py)|Easy