restructured

seminar03_initialization/01_letter_case_switch/main.cpp

@@ -0,0 +1,22 @@
+#include <iostream>
+#include <string>
+#include <cctype>
+
+using namespace std;
+
+string letter_case_switch(const string & str)
+{
+    string result = str;
+    if (str.size() == 0)
+	return result;
+    result[0] =
+	isupper(result[0]) ? tolower(result[0]) : toupper(result[0]);
+    return result;
+}
+
+int main()
+{
+    string meow;
+    cin >> meow;
+    cout << letter_case_switch(meow) << endl;
+}

seminar03_initialization/01_letter_case_switch/main.cpp~

@@ -0,0 +1,19 @@
+#include <iostream>
+#include <string>
+#include <cctype>
+
+using namespace std;
+
+string letter_case_switch(const string& str) {
+    string result = str;
+    if (str.size() == 0)
+        return result;  
+    result[0] = isupper(result[0]) ? tolower(result[0]) : toupper(result[0]);
+    return result;
+}
+
+int main() {
+        string meow;
+        cin >> meow;
+        cout << letter_case_switch(meow) << endl;
+}

seminar03_initialization/02_repeat/main.cpp

@@ -0,0 +1,48 @@
+#include <iostream>
+#include <string>
+#include <string_view>
+
+using namespace std;
+
+string repeat1(string_view s)
+{
+    return string {
+    s}
+    +string {
+    s};
+}
+
+void repeat2(string & s)
+{
+    s += s;
+}
+
+void repeat3(string * s)
+{
+    *s += *s;
+}
+
+string *repeat4(string_view s)
+{
+    string *result = new string;
+    *result = string {
+    s} +string {
+    s};
+    return result;
+}
+
+int main()
+{
+    string meow;
+    cin >> meow;
+
+    cout << "test of repeat1:" << endl << repeat1(meow) << endl;
+
+    repeat2(meow);
+    cout << "test of repeat2:" << endl << meow << endl;
+
+    repeat3(&meow);
+    cout << "test of repeat3:" << endl << meow << endl;
+
+    cout << "test of repeat4:" << endl << *repeat4(meow) << endl;
+}

seminar03_initialization/02_repeat/main.cpp~

@@ -0,0 +1,38 @@
+#include <iostream>
+#include <string>
+#include <string_view>
+
+using namespace std;
+
+string repeat1(string_view s) {
+    return string{s} + string{s};
+}
+
+void repeat2(string& s) {
+    s += s;
+}
+
+void repeat3(string* s) {
+    *s += *s;
+}
+
+string* repeat4(string_view s) {
+    string* result = new string;
+    *result = string{s} + string{s};
+    return result;
+}
+
+int main() {
+        string meow;
+        cin >> meow;
+
+        cout << "test of repeat1:" << endl << repeat1(meow) << endl;
+        
+        repeat2(meow);
+        cout << "test of repeat2:" << endl << meow << endl;       
+
+        repeat3(&meow);
+        cout << "test of repeat3:" << endl << meow << endl;       
+        
+        cout << "test of repeat4:" << endl << *repeat4(meow) << endl;       
+}

seminar03_initialization/03_string_multiplication/main.cpp

@@ -0,0 +1,24 @@
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+string operator*(const string str, int n) {
+    string result;
+    for (int i = 0; i < n; ++i)
+        result += str; 
+    return result;
+}
+
+string operator*(int n, const string str) {
+    string result;
+    for (int i = 0; i < n; ++i)
+        result += str; 
+    return result;
+}
+
+int main() {
+    string meow;
+    cin >> meow;
+    cout << 3 * meow << endl;
+}

seminar03_initialization/04_truncate_to_dot/main.cpp

@@ -0,0 +1,22 @@
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+void truncateToDot(string& s) {
+    s.resize(s.find('.'));
+    s.shrink_to_fit();
+}
+
+int main() {
+    std::string a = "cat.dog.mouse.elephant.tiger.lion";
+    std::string b = "wikipedia.org";
+    std::string c = ".com";
+    truncateToDot(a);
+    truncateToDot(b);
+    truncateToDot(c);
+
+    cout << a << endl
+         << b << endl
+         << c << endl;
+}

seminar03_initialization/05_string_sum/main.cpp

@@ -0,0 +1,35 @@
+#include <iostream>
+#include <cstdio>
+#include <string>
+
+using namespace std;
+
+int string_sum(const string& str) {
+    int res = 0;
+    int x;
+    int n = str.size();
+    int i = 0;
+    while (i < n) {
+       switch (str[i]) {
+            case '[':
+            case ',' : 
+                    sscanf((str.c_str()) + i + 1, "%d", &x);
+                    res += x;
+                    break;
+            case ']' :
+                    return res;
+            case ' ':
+                    break;
+            default:
+                    break;
+       } 
+       ++i;
+    }
+    return -1;
+}
+
+int main() {
+    string meow;
+    getline(cin, meow);
+    cout << string_sum(meow) << endl;
+}

seminar03_initialization/06_new/main.cpp

@@ -0,0 +1,34 @@
+#include <iostream>
+#include <string>
+#include <string_view>
+
+using namespace std;
+
+int main() {
+    int *x = new int{123};
+    cout << *x << endl;
+
+    string *str = new string{"Cats and Dogs"};
+    cout << *str << endl;
+
+    int *xs = new int[]{10, 20, 30, 40, 50};
+    for (int i = 0; i < 5; ++i)
+            cout << xs[i] << " ";
+    cout << endl;
+
+    string *strs = new string[]{"Cat", "Dog", "Mouse"};
+    for (int i = 0; i < 3; ++i)
+            cout << strs[i] << " ";
+    cout << endl;
+
+    string_view *str_views = new string_view[]{strs[0], strs[1], strs[2]};
+    for (int i = 0; i < 3; ++i)
+            cout << str_views[i] << " ";
+    cout << endl;
+
+    delete x;
+    delete str;
+    delete[] xs;
+    delete[] strs;
+    delete[] str_views;
+}

seminar03_initialization/08_stringview/main.cpp

@@ -0,0 +1,16 @@
+#include <iostream>
+#include "miptstring.cpp"
+#include "miptstringview.cpp"
+
+using namespace std;
+
+int main() {
+        mipt::String str = "Meow!!";
+        cout << str << endl;
+        mipt::StringView sv = str;
+        cout << "string view: " << sv << endl; 
+        char a[] = "nyaa!";
+        mipt::StringView sv1 = a;
+       cout << "string view: " << sv1 << endl; 
+       cout << sv1.at(200) << endl;
+}

seminar03_initialization/08_stringview/miptstring.cpp

@@ -0,0 +1,221 @@
+#pragma once
+
+#include <iostream>
+#include <algorithm>
+#include <cstdlib>
+#include <cstring>
+using std::cout, std::cin, std::endl, std::size_t;
+
+namespace mipt{
+
+char* errorCheckedMalloc(size_t newCapacity)
+{
+    char* result = static_cast<char*>(std::malloc(newCapacity * sizeof(char)));
+    if (result == NULL)
+    {
+        cout << "Error! Out of memory" << endl;
+        std::exit(1);
+    }
+    return result;
+}
+
+
+class String 
+{
+private:
+
+    size_t mSize        {0};
+    size_t mCapacity    {0};
+    char* mpData        {nullptr};
+
+public:
+
+    String(const char* str) 
+    {
+        size_t strSize = std::strlen(str);
+        resize(strSize);
+        std::memcpy(mpData, str, mSize);
+    }
+
+    String() : String("") {}
+    String(const String& s) : String(s.cStr()) {}
+
+    String(size_t n, char a)
+    {
+        resize(n);
+
+        for (size_t i = 0; i < mSize; ++i)
+            mpData[i] = a;
+    }
+
+    ~String()
+    {
+        std::free(mpData);
+    }
+
+    void reserve(size_t capacity)
+    {
+        if (capacity <= mCapacity)
+            return;
+
+        mCapacity = std::max(2 * mCapacity, capacity);
+        char* newData = errorCheckedMalloc(mCapacity);
+
+        if (mpData)
+            std::memcpy(newData, mpData, mSize + 1);
+
+        std::free(mpData);
+        mpData = newData;
+    }
+
+
+    void resize(size_t size)
+    {
+        reserve(size + 1);
+        mSize = size;
+        mpData[mSize] = '\0';
+    }
+
+
+    String& operator=(const String& right)
+    {
+        if (this == &right)
+            return *this;
+
+        mSize = right.mSize;
+        resize(mSize);
+
+        std::memcpy(mpData, right.mpData, mSize + 1);
+
+        return *this;
+    }
+
+
+    String operator+(const String& b)
+    {
+        String result;
+        result.resize(mSize + b.mSize);
+
+        std::memcpy(result.mpData, mpData, mSize);
+        std::memcpy(result.mpData + mSize, b.mpData, b.mSize);
+        result.mpData[result.mSize] = '\0';
+
+        return result;
+    }
+
+    String& operator+=(const String& right)
+    {
+        *this = *this + right;
+        return *this;
+    }
+
+    bool operator==(const String& right) const
+    {
+        if (mSize != right.mSize)
+            return false;
+
+        size_t i = 0;
+        while (i < mSize && mpData[i] == right.mpData[i])
+            i++;
+
+        return i == mSize;
+    }
+
+    bool operator<(const String& right) const
+    {
+        size_t i = 0;
+        while (i < mSize && i < right.mSize && mpData[i] == right.mpData[i])
+            i++;
+
+        return mpData[i] < right.mpData[i];
+    }
+
+    bool operator<=(const String& right) const
+    {
+        size_t i = 0;
+        while (i < mSize && i < right.mSize && mpData[i] == right.mpData[i])
+            i++;
+
+        return mpData[i] <= right.mpData[i];
+    }
+
+    bool operator!=(const String& right) const
+    {
+        return !(*this == right);
+    }
+
+    bool operator>(const String& right) const
+    {
+        return !(*this <= right);
+    }
+
+    bool operator>=(const String& right) const
+    {
+        return !(*this < right);
+    }
+
+    char& operator[](size_t i)
+    {
+        return mpData[i];
+    }
+
+    const char& operator[](size_t i) const
+    {
+        return mpData[i];
+    }
+
+    char& at(size_t i)
+    {
+        if (i >= mSize)
+        {
+            cout << "Error! Index is out of bounds." << endl;
+        }
+        return mpData[i];
+    }
+
+    void clear()
+    {
+        std::free(mpData);
+
+        mSize = 0;
+        mCapacity = 1;
+        mpData = errorCheckedMalloc(mCapacity);
+        mpData[0] = '\0';
+    }
+
+    void addCharacter(char c)
+    {
+        if (mSize + 1 == mCapacity)
+            reserve(2 * mCapacity);
+
+        mpData[mSize] = c;
+        resize(mSize + 1);
+    }
+
+
+    size_t getSize()        const   {return mSize;}
+    size_t getCapacity()    const   {return mCapacity;}
+    const char* cStr()      const   {return mpData;}
+};
+
+
+std::ostream& operator<<(std::ostream& out, const String& s) 
+{
+    out << s.cStr();
+    return out;
+}
+
+std::istream& operator>>(std::istream& in, String& s) 
+{
+    s.clear();
+    while (true)
+    {
+        char x = in.get();
+        if (x == ' ' || x == '\n' || x == '\t')
+            break;
+        s.addCharacter(x);
+    }
+    return in;
+}
+
+}

seminar03_initialization/08_stringview/miptstringview.cpp

@@ -0,0 +1,59 @@
+#pragma once
+
+#include <iostream>
+#include <algorithm>
+#include <cstdlib>
+#include <cstring>
+using std::cout, std::cin, std::endl, std::size_t;
+
+namespace mipt {
+
+class StringView 
+{
+private:
+    const char* mpData;
+    size_t mSize;
+  
+public:  
+    StringView() {;
+        mSize = 0;
+        mpData = nullptr;
+    }
+    StringView(const StringView& str) {
+        mSize = str.mSize;
+        mpData = str.mpData;
+    }
+    StringView(const mipt::String& s) {
+        mSize = s.getSize();
+        mpData = s.cStr();  
+    }
+    StringView(const char* s) {
+        mpData = s;
+        mSize = strlen(s); 
+    }
+    const char& at(size_t i)
+    {
+        if (i >= mSize)
+        {
+            throw std::out_of_range("Error! Index is out of bounds.");
+            std::exit(1);
+        }
+        return mpData[i];
+    }
+    const char& operator[](size_t i)
+    {
+        return mpData[i];
+    }
+    size_t size() {
+        return mSize;
+    }
+
+};
+}
+
+std::ostream& operator<<(std::ostream& out, mipt::StringView sv) {
+    size_t size = sv.size();
+    for (int i = 0; i < size; ++i)
+            out << sv[i];
+    return out; 
+}