Add solutions to all exercises in chapter 5.

README.md

@@ -1,4 +1,6 @@
-# Cpp-Primer-5th-Exercises
+# Solutions to Exercises in **C++ Primer** 5th Edition
+
+This repo is the solutions to exercises in book _C++ Primer_ (5th Edition). All files except explicitly announced are under [Apache License](http://www.apache.org/licenses/LICENSE-2.0).
 
 ### Contents
 
@@ -39,15 +41,15 @@
 [21](ch4/4.21.cpp)|[22](ch4/4.22.cpp)|[23](ch4/4.23.cpp)|[24](ch4/4.24.md)|[25](ch4/4.25.md)|[26](ch4/4.26.md)|[27](ch4/4.27.cpp)|[28](ch4/4.28.cpp)|[29](ch4/4.29.cpp)|[30](ch4/4.30.md)|
 [31](ch4/4.31.cpp)|[32](ch4/4.32.cpp)|[33](ch4/4.33.md)|[34](ch4/4.34.md)|[35](ch4/4.35.cpp)|[36](ch4/4.36.cpp)|[37](ch4/4.37.cpp)|[38](ch4/4.38.md)
 
-<!---
-#### Chapter 5 [](ch5)
+#### Chapter 5 [Statements](ch5)
 
  1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10
 --:|--:|--:|--:|--:|--:|--:|--:|--:|--:
-[1](ch5/5.1.cpp)|[2](ch5/5.2.cpp)|[3](ch5/5.3.cpp)|[4](ch5/5.4.cpp)|[5](ch5/5.5.cpp)|[6](ch5/5.6.cpp)|[7](ch5/5.7.cpp)|[8](ch5/5.8.cpp)|[9](ch5/5.9.cpp)|[10](ch5/5.10.cpp)|
-[11](ch5/5.11.cpp)|[12](ch5/5.12.cpp)|[13](ch5/5.13.cpp)|[14](ch5/5.14.cpp)|[15](ch5/5.15.cpp)|[16](ch5/5.16.cpp)|[17](ch5/5.17.cpp)|[18](ch5/5.18.cpp)|[19](ch5/5.19.cpp)|[20](ch5/5.20.cpp)|
-[21](ch5/5.21.cpp)|[22](ch5/5.22.cpp)|[23](ch5/5.23.cpp)|[24](ch5/5.24.cpp)|[25](ch5/5.25.cpp)
+[1](ch5/5.1.md))|[2](ch5/5.2.md)|[3](ch5/5.3.cpp)|[4](ch5/5.4.md)|[5](ch5/5.5.cpp)|[6](ch5/5.6.cpp)|[7](ch5/5.7.md)|[8](ch5/5.8.md)|[9](ch5/5.9.cpp)|[10](ch5/5.10.cpp)|
+[11](ch5/5.11.cpp)|[12](ch5/5.12.cpp)|[13](ch5/5.13.md)|[14](ch5/5.14.cpp)|[15](ch5/5.15.md)|[16](ch5/5.16.cpp)|[17](ch5/5.17.cpp)|[18](ch5/5.18.md)|[19](ch5/5.19.cpp)|[20](ch5/5.20.cpp)|
+[21](ch5/5.21.cpp)|[22](ch5/5.22.md)|[23](ch5/5.23.cpp)|[24](ch5/5.24.cpp)|[25](ch5/5.25.cpp)
 
+<!---
 #### Chapter 6 [](ch6)
 
  1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10

ch4/4.2.md

@@ -1,9 +1,7 @@
-(a)
-    * vec.begin()  ==>  * ((vec.begin)())
+(a) `* vec.begin()  ==>  * ((vec.begin)())`
 
 The order is: member selector, function call, dereference.
 
-(b)
-    * vec.begin() + 1  ==>  ( * ((vec.begin)())) + 1
+(b) `* vec.begin() + 1  ==>  ( * ((vec.begin)())) + 1`
 
 The order is: member selector, function call, dereference, add.

ch5/5.1.md

@@ -0,0 +1 @@
+A single `;`(semicolon) is a null statement. It is used where the language requires a statement but the program's logic does not.

ch5/5.10.cpp

@@ -0,0 +1,32 @@
+#include <iostream>
+
+int main() {
+  unsigned aCnt = 0, eCnt = 0, iCnt = 0, oCnt = 0, uCnt = 0;
+  char ch;
+  while (std::cin >> ch) {
+    switch(ch) {
+      case 'A': case 'a':
+        ++aCnt;
+        break;
+      case 'E': case 'e':
+        ++eCnt;
+        break;
+      case 'I': case 'i':
+        ++iCnt;
+        break;
+      case 'O': case 'o':
+        ++oCnt;
+        break;
+      case 'U': case 'u':
+        ++uCnt;
+        break;
+    }
+  }
+  std::cout << "Number of vowel a: " << aCnt << '\n'
+            << "Number of vowel e: " << eCnt << '\n'
+            << "Number of vowel i: " << iCnt << '\n'
+            << "Number of vowel o: " << oCnt << '\n'
+            << "Number of vowel u: " << uCnt << std::endl;
+
+  return 0;
+}

ch5/5.11.cpp

@@ -0,0 +1,48 @@
+#include <iostream>
+
+int main() {
+  unsigned aCnt = 0, eCnt = 0, iCnt = 0, oCnt = 0, uCnt = 0;
+  unsigned spaceCnt = 0, tabCnt = 0, newlineCnt = 0, otherCnt = 0;
+  char ch;
+  while (std::cin.get(ch)) {  // `<<` operator will omit whitespace characters
+    switch(ch) {
+      case 'A': case 'a':
+        ++aCnt;
+        break;
+      case 'E': case 'e':
+        ++eCnt;
+        break;
+      case 'I': case 'i':
+        ++iCnt;
+        break;
+      case 'O': case 'o':
+        ++oCnt;
+        break;
+      case 'U': case 'u':
+        ++uCnt;
+        break;
+      case ' ':
+        ++spaceCnt;
+        break;
+      case '\t':
+        ++tabCnt;
+        break;
+      case '\n':
+        ++newlineCnt;
+        break;
+      default:
+        ++otherCnt;
+    }
+  }
+  std::cout << "Number of vowel a:\t" << aCnt << '\n'
+            << "Number of vowel e:\t" << eCnt << '\n'
+            << "Number of vowel i:\t" << iCnt << '\n'
+            << "Number of vowel o:\t" << oCnt << '\n'
+            << "Number of vowel u:\t" << uCnt << '\n'
+            << "Number of space:\t" << spaceCnt << '\n'
+            << "Number of tab:\t" << tabCnt << '\n'
+            << "Number of newline:\t" << newlineCnt << '\n'
+            << "Number of others:\t" << otherCnt << std::endl;
+
+  return 0;
+}

ch5/5.11.in

@@ -0,0 +1,16 @@
+Exercise 5.9: Write a program using a series of if statements to count the number of
+	vowels in text read from cin.
+
+Exercise 5.10: There is one problem with our vowel-counting program as we’ve implemented
+	it: It doesn’t count capital letters as vowels. Write a program that counts
+	both lower- and uppercase letters as the appropriate vowel—that is, your program
+	should count both ’a’ and ’A’ as part of aCnt, and so forth.
+
+Exercise 5.11: Modify our vowel-counting program so that it also counts the number
+	of blank spaces, tabs, and newlines read.
+
+Exercise 5.12: Modify our vowel-counting program so that it counts the number of
+	occurrences of the following two-character sequences: ff, fl, and fi.
+
+Exercise 5.13: Each of the programs in the highlighted text on page 184 contains a
+	common programming error. Identify and correct each error.

ch5/5.12.cpp

@@ -0,0 +1,72 @@
+#include <iostream>
+
+int main() {
+  unsigned aCnt = 0, eCnt = 0, iCnt = 0, oCnt = 0, uCnt = 0;
+  unsigned spaceCnt = 0, tabCnt = 0, newlineCnt = 0, otherCnt = 0;
+  unsigned ffCnt = 0, flCnt = 0, fiCnt = 0;
+  bool fPresent = false;
+  char ch;
+  while (std::cin.get(ch)) {  // `<<` operator will omit whitespace characters
+    switch(ch) {
+      case 'A': case 'a':
+        ++aCnt;
+        break;
+      case 'E': case 'e':
+        ++eCnt;
+        break;
+      case 'I':
+        ++iCnt;
+        break;
+      case 'i':
+        ++iCnt;
+        if (fPresent) {
+          ++fiCnt;
+          fPresent = false;
+        }
+        break;
+      case 'O': case 'o':
+        ++oCnt;
+        break;
+      case 'U': case 'u':
+        ++uCnt;
+        break;
+      case ' ':
+        ++spaceCnt;
+        break;
+      case '\t':
+        ++tabCnt;
+        break;
+      case '\n':
+        ++newlineCnt;
+        break;
+      case 'f':
+        if (fPresent)
+          ++ffCnt;
+        else
+          fPresent = true;
+        break;
+      case 'l':
+        if (fPresent) {
+          ++flCnt;
+          fPresent = false;
+        }
+        break;
+      default:
+        ++otherCnt;
+    }
+  }
+  std::cout << "Number of vowel a:\t" << aCnt << '\n'
+            << "Number of vowel e:\t" << eCnt << '\n'
+            << "Number of vowel i:\t" << iCnt << '\n'
+            << "Number of vowel o:\t" << oCnt << '\n'
+            << "Number of vowel u:\t" << uCnt << '\n'
+            << "Number of space:\t" << spaceCnt << '\n'
+            << "Number of tab:\t" << tabCnt << '\n'
+            << "Number of newline:\t" << newlineCnt << '\n'
+            << "Number of sequence ff:\t" << ffCnt << '\n'
+            << "Number of sequence fl:\t" << flCnt << '\n'
+            << "Number of sequence fi:\t" << fiCnt << '\n'
+            << "Number of others:\t" << otherCnt << std::endl;
+
+  return 0;
+}

ch5/5.13.md

@@ -0,0 +1,59 @@
+(a)
+
+    unsigned aCnt = 0, eCnt = 0, iouCnt = 0;
+    char ch = next_text();
+    switch (ch) {
+      case ’a’: aCnt++; break;  // Need `break`
+      case ’e’: eCnt++; break;  // Need `break`
+      default: iouCnt++;
+    }
+
+(b)
+
+    unsigned index = some_value();
+    int ix;
+    switch (index) {
+      case 1:
+        //int ix = get_value();  // Cannot bypass initialization
+        ix = get_value();
+        ivec[ ix ] = index;
+        break;
+      default:
+        ix = ivec.size()-1;
+        ivec[ ix ] = index;
+    }
+
+(c)
+
+    unsigned evenCnt = 0, oddCnt = 0;
+    int digit = get_num() % 10;
+    switch (digit) {
+      //case 1, 3, 5, 7, 9:  // case label must be integral const expression
+      case 1: case 3: case 5: case 7: case 9:
+        oddcnt++;
+        break;
+      //case 2, 4, 6, 8, 10:
+      case 2: case 4: case 6: case 8: case 10:
+        evencnt++;
+        break;
+    }
+
+(d)
+
+    //unsigned ival=512, jval=1024, kval=4096;
+    // case label must be integral const expression
+    constexpr unsigned ival=512, jval=1024, kval=4096;
+    unsigned bufsize;
+    unsigned swt = get_bufCnt();
+    switch(swt) {
+      case ival:
+        bufsize = ival * sizeof(int);
+        break;
+      case jval:
+        bufsize = jval * sizeof(int);
+        break;
+      case kval:
+        bufsize = kval * sizeof(int);
+        break;
+    }
+

ch5/5.14.cpp

@@ -0,0 +1,27 @@
+#include <iostream>
+#include <string>
+
+int main() {
+  std::string word, duplicatedWord, maxDuplicatedWord;
+  unsigned cnt = 0, maxCnt = 0;
+  while (std::cin >> word) {
+    if (word == duplicatedWord)
+      ++cnt;
+    else {
+      if (cnt > maxCnt) {
+        maxDuplicatedWord = duplicatedWord;
+        maxCnt = cnt;
+      }
+      duplicatedWord = word;
+      cnt = 1;
+    }
+  }
+  if (cnt > maxCnt) {
+    maxDuplicatedWord = duplicatedWord;
+    maxCnt = cnt;
+  }
+  std::cout << maxDuplicatedWord << " occurs " << maxCnt
+            << " time" << (maxCnt > 1 ? "s" : "") << ". " << std::endl;
+
+  return 0;
+}

ch5/5.15.md

@@ -0,0 +1,21 @@
+(a)
+
+    int ix;
+    for (ix = 0; ix != sz; ++ix) { /* ... */ }
+    //for (int ix = 0; ix != sz; ++ix) { /* ... */ }
+    // The loop variable is used outside `for` scope, thus should be defined outside.
+    if (ix != sz)
+    // ...
+
+(b)
+
+    int ix;
+    //for (ix != sz; ++ix) { /* ... */ }
+    // When the initialization is unnecessary, a null statement should be used.
+    for (; ix != sz; ++ix) { /* ... */ }
+
+(c)
+
+    for (int ix = 0; ix != sz; ++ix, ++ sz) { /* ... */ }
+    // The loop will never end.
+    for (int ix = 0; ix != sz; ++ix) { /* ... */ }

ch5/5.16.cpp

@@ -0,0 +1,21 @@
+#include <iostream>
+#include <vector>
+
+int main() {
+  int i;
+  while (std::cin >> i) { /* ... */ }
+  for (int j; std::cin >> j;) { /* ... */ }
+
+  std::vector<int> iv(10, 1);
+  for (auto it = iv.begin(); it != iv.end(); ++it) { /* ... */ }
+  auto it2 = iv.begin();
+  while (it2 != iv.end()) {
+    ++it2;
+    /* ... */
+  }
+
+  // I would choose `for`-loop, because it can do what a `while`-loop can, but
+  // not vise versa.
+
+  return 0;
+}

ch5/5.17.cpp

@@ -0,0 +1,33 @@
+#include <iostream>
+#include <vector>
+#include <string>
+#include <sstream>
+
+void readVector(std::vector<int> &v) {
+  std::string str;
+  std::getline(std::cin, str);
+  std::stringstream ss(str);
+  int i;
+  while(ss >> i)
+    v.push_back(i);
+  //for (const auto &e : v)
+  //  std::cout << e << " ";
+  //std::cout << std::endl;
+}
+
+bool isPrefix(const std::vector<int> &v1, const std::vector<int> &v2) {
+  auto it1 = v1.cbegin(), it2 = v2.cbegin();
+  for (; it1 != v1.cend() && it2 != v2.cend(); ++it1, ++it2)
+    if (*it1 != *it2)
+      break;
+  return it1 == v1.cend() || it2 == v2.cend();
+}
+
+int main() {
+  std::vector<int> v1, v2;
+  readVector(v1);
+  readVector(v2);
+  std::cout << (isPrefix(v1, v2) ? "true" : "false") << std::endl;
+
+  return 0;
+}