Interview Preparation kit added

Interview Preparation Kit - CPP/01. Warm-up Challenges/001. Sock Merchant.cpp

@@ -0,0 +1,25 @@
+// Problem: https://www.hackerrank.com/challenges/sock-merchant/problem
+// Score: 10
+
+
+#include <iostream>
+
+
+int main() {
+    int n, element;
+    int arr[101] = {0};
+    int ans = 0;
+
+    std::cin >> n;
+
+    for (int i = 0; i < n; i++) {
+        std::cin >> element;
+        arr[element]++;
+
+        ans += arr[element] / 2;
+        arr[element] = arr[element] % 2;
+    }
+
+    std::cout << ans << std::endl;
+    return 0;
+}

Interview Preparation Kit - CPP/01. Warm-up Challenges/002. Counting Valleys.cpp

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+// Problem: https://www.hackerrank.com/challenges/counting-valleys/problem
+// Score: 15
+
+#include <iostream>
+#include <string>
+using namespace std;
+
+int main() {
+    int n;
+    cin >> n;
+
+    string str;
+    cin >> str;
+
+    int ans = 0;
+
+    int current_level = 0;
+
+    for (char c: str){
+        if (c == 'D') {
+            if (current_level == 0){
+                ans++;
+            }
+
+            current_level--;
+        }
+
+        else if (c == 'U') current_level++;
+    }
+
+    cout << ans;
+
+    return 0;
+}

Interview Preparation Kit - CPP/01. Warm-up Challenges/003. Jumping on the Clouds.cpp

@@ -0,0 +1,34 @@
+// Problem: https://www.hackerrank.com/challenges/jumping-on-the-clouds/problem
+// Score: 20
+
+
+#include <iostream>
+#include <vector>
+using namespace std;
+
+int main(){
+    int n;
+    cin >> n;
+
+    int element;
+    vector<int> arr;
+
+    while (cin >> element){
+        arr.push_back(element);
+    }
+
+    int ans = 0;
+    int position = 0;
+
+    while (position < n - 1){
+        position ++;
+        if (position + 1 <= n - 1 && arr[position + 1] != 1){
+            position ++;
+        }
+        ans ++;
+    }
+
+    cout << ans;
+
+    return 0;
+}

Interview Preparation Kit - CPP/01. Warm-up Challenges/004. Repeated String.cpp

@@ -0,0 +1,32 @@
+// Problem: https://www.hackerrank.com/challenges/repeated-string/problem
+// Score: 20
+
+
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+
+long long count(string const & str){
+    long long ans = 0;
+    for (const char & c: str){
+        ans += c == 'a';
+    }
+    return ans;
+}
+
+
+int main(){
+    string str;
+    cin >> str;
+
+    long long n;
+    cin >> n;
+
+    long long ans = 0;
+    ans = n / str.size() * count(str) + count(str.substr(0, n % str.size()));
+
+    cout << ans;
+    return 0;
+}

Interview Preparation Kit - CPP/01. Warm-up Challenges/CMakeLists.txt

@@ -0,0 +1,8 @@
+cmake_minimum_required (VERSION 3.8)
+
+project(warm-up)
+
+add_executable(task-1 "001. Sock Merchant.cpp")
+add_executable(task-2 "002. Counting Valleys.cpp")
+add_executable(task-3 "003. Jumping on the Clouds.cpp")
+add_executable(task-4 "004. Repeated String.cpp")

Interview Preparation Kit - CPP/02. Arrays/001. 2D Array - DS.cpp

@@ -0,0 +1,38 @@
+// Problem: https://www.hackerrank.com/challenges/2d-array/problem
+// Score: 15
+
+
+#include <iostream>
+using namespace std;
+
+int hourglass_sum(int arr[6][6], int i, int j){
+    int ans = 0;
+    ans = arr[i][j] + arr[i][j + 1] + arr[i][j + 2] +
+            arr[i + 1][j + 1] +
+            arr[i + 2][j] + arr[i + 2][j + 1] + arr[i + 2][j + 2];
+    return ans;
+}
+
+
+int main(){
+
+    int arr[6][6];
+
+    for (auto & i : arr){
+        for (int & j : i){
+            cin >> j;
+        }
+    }
+
+    int ans = -1000;
+    for (int i = 0; i < 4; i++){
+        for (int j = 0; j < 4; j++){
+            if (hourglass_sum(arr, i, j) > ans){
+                ans = hourglass_sum(arr, i, j);
+            }
+        }
+    }
+
+    cout << ans;
+    return 0;
+}

Interview Preparation Kit - CPP/02. Arrays/002. Arrays - Left Rotation.cpp

@@ -0,0 +1,27 @@
+// Problem: https://www.hackerrank.com/challenges/ctci-array-left-rotation/problem
+// Score: 20
+
+
+#include <iostream>
+#include <vector>
+using namespace std;
+
+int main(){
+    int n, d;
+
+    cin >> n;
+    cin >> d;
+
+    vector<int> arr;
+    for (int i = 0; i < n; i++){
+        int tmp;
+        cin >> tmp;
+        arr.push_back(tmp);
+    }
+
+    for (int i = 0; i < n; i++){
+        cout << arr[(i + d) % n] << " ";
+    }
+
+    return 0;
+}

Interview Preparation Kit - CPP/02. Arrays/003. New Year Chaos.cpp

@@ -0,0 +1,56 @@
+// Problem: https://www.hackerrank.com/challenges/new-year-chaos/problem
+//  Score: 40
+
+#include <iostream>
+#include <vector>
+using namespace std;
+
+
+bool check_sorted(vector<int> & arr){
+    bool ans = true;
+    for (int i = 0; i < arr.size() - 1; i++){
+        if (arr[i] > arr[i + 1]){
+            ans = false;
+        }
+    }
+    return ans;
+}
+
+
+int main(){
+    int t;
+    cin >> t;
+
+    for (int i = 0; i < t; i++){
+        int n;
+        cin >> n;
+        vector<int> arr;
+
+        for (int j = 0; j < n; j++){
+            int tmp;
+            cin >> tmp;
+            arr.push_back(tmp);
+        }
+
+        int ans = 0;
+
+        for (int j = 0; j < 2; j++){
+            for (int k = arr.size() - 1; k > 0; k--){
+                if (arr[k] < arr[k - 1]){
+                    swap(arr[k], arr[k - 1]);
+                    ans++;
+                }
+            }
+        }
+
+        if (check_sorted(arr)){
+            cout << ans << endl;
+        }
+        else {
+            cout << "Too chaotic" << endl;
+        }
+
+    }
+
+    return 0;
+}

Interview Preparation Kit - CPP/02. Arrays/004. Minimum Swaps 2.cpp

@@ -0,0 +1,36 @@
+// Problem: https://www.hackerrank.com/challenges/minimum-swaps-2/problem
+// Score: 40
+
+
+#include <iostream>
+#include <vector>
+using namespace std;
+
+
+int main(){
+    int n;
+    cin >> n;
+    vector<int> arr;
+
+    for (int i = 0; i < n; i++){
+        int tmp;
+        cin >> tmp;
+        arr.push_back(tmp - 1);
+    }
+
+    int i = 0;
+    int ans = 0;
+    while (i < n){
+        if (arr[i] != i){
+            swap(arr[i], arr[arr[i]]);
+            ans++;
+        }
+        else{
+            i++;
+        }
+    }
+
+    cout << ans;
+
+    return 0;
+}

Interview Preparation Kit - CPP/02. Arrays/005. Array Manipulation.cpp

@@ -0,0 +1,36 @@
+// Problem: https://www.hackerrank.com/challenges/crush/problem
+// Score: 60
+
+
+#include <iostream>
+#include <vector>
+using namespace std;
+
+
+int main(){
+    int n, m;
+    cin >> n >> m;
+
+    vector<long long int> arr(n, 0);
+
+    for (int i = 0; i < m; i++){
+        int start, finish, value;
+        cin >> start >> finish >> value;
+        arr[start - 1] += value;
+        arr[finish] -= value;
+    }
+
+    long long int ans = 0;
+    long long int current = 0;
+
+    for (int value: arr){
+        current += value;
+        if (current > ans){
+            ans = current;
+        }
+    }
+
+    cout << ans;
+
+    return 0;
+}

Interview Preparation Kit - CPP/02. Arrays/CMakeLists.txt

@@ -0,0 +1,9 @@
+cmake_minimum_required (VERSION 3.8)
+
+project(arrays)
+
+add_executable(task-1 001.\ 2D\ Array\ -\ DS.cpp)
+add_executable(task-2 002.\ Arrays\ -\ Left\ Rotation.cpp)
+add_executable(task-3 003.\ New\ Year\ Chaos.cpp)
+add_executable(task-4 004.\ Minimum\ Swaps\ 2.cpp)
+add_executable(task-5 005.\ Array\ Manipulation.cpp)

Interview Preparation Kit - CPP/03. Dictionaries and Hashmaps/001. Hash Tables - Ransom Note.cpp

@@ -0,0 +1,48 @@
+// Problem: https://www.hackerrank.com/challenges/ctci-ransom-note/problem
+// Score: 25
+
+#include <iostream>
+#include <string>
+#include <map>
+using namespace std;
+
+
+int main(){
+    int m, n;
+    cin >> m >> n;
+
+    map<string, int> magazine;
+
+    for (int i = 0; i < m; i++) {
+        string word;
+        cin >> word;
+
+        if (magazine.find(word) == magazine.end()){
+            magazine[word] = 1;
+        }
+        else {
+            magazine[word]++;
+        }
+    }
+
+
+    bool ans = true;
+    for (int i = 0; i < n; i++){
+        string word;
+        cin >> word;
+
+        if (magazine.find(word) == magazine.end() || magazine[word] == 0){
+            ans = false;
+            break;
+        }
+        else {
+            magazine[word]--;
+        }
+    }
+
+
+    if (ans) cout << "Yes" << endl;
+    else cout << "No" << endl;
+
+    return 0;
+}