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Selection Sorting

Selection Sorting. Pseudocode (Forward) for i = 0 to size - 2 find the index of the required element between s[i] and s[size - 1] If i not the same as index swap s[i] and s[index] -----. Selection Sorting. Pseudocode (Backward) for i = size – 1 to 1

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Selection Sorting

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  1. Selection Sorting Pseudocode (Forward) for i = 0 to size - 2 find the index of the required element between s[i] and s[size - 1] If i not the same as index swap s[i] and s[index] -----

  2. Selection Sorting Pseudocode (Backward) for i = size – 1 to 1 find the index of the required element between s[0] and s[i] If i not the same as index swap s[i] and s[index] -----

  3. Sorting Array of Structs Sort Student by GPA (Descending) and ID (Ascending) StudentType s[MAX_SIZE]; int size; for i = 0 to size - 2 find the index of the required student between s[i] and s[size - 1] If i not the same as index swap s[i] and s[index] -----

  4. Function IndexOfTheStudent // The function finds and returns the index of the // student who has the highest GPA between s[first] and s[last]; // if two or more students have the same highest GPA, return // the index of student with the smallest ID. // Parameters: (In, In, In) int IndexOfTheStudent(const StudentType s[], int first, int last) { int index = first; for (int i = first + 1; i <= last; i++) { // How to compare two students on GPA and ID if ( ) index = i; } return index; } -----

  5. Function CompGPA_ID // The function compares two students: // It returns true if s1 has higher GPA, or // s1 has the same GPA as s2 but has a smaller ID // It returns false otherwise. // Parameters: ( In, In) bool CompGPA_ID(const StudentType& s1, const StudentType& s2) { if (s1.gpa > s2.gpa) return true; else if (s1.gpa == s2.gpa && s1.id < s2.id) return true; else return false; } -----

  6. Function CompGPA_ID // The function compares two students: // It returns true if s1 has higher GPA, or // s1 has the same GPA as s2 but has a smaller ID // It returns false otherwise. // Parameters: ( In, In) bool CompGPA_ID(const StudentType& s1, const StudentType& s2) { if (s1.gpa > s2.gpa || (s1.gpa == s2.gpa && s1.id < s2.id)) return true; else return false; } -----

  7. Function CompGPA_ID // The function compares two students: // It returns true if s1 has higher GPA, or // s1 has the same GPA as s2 but has a smaller ID // It returns false otherwise. // Parameters: ( In, In) bool CompGPA_ID(const StudentType& s1, const StudentType& s2) { return ((s1.gpa > s2.gpa) || (s1.gpa == s2.gpa && s1.id < s2.id)); } -----

  8. Function IndexOfTheStudent // The function finds and returns the index of the // student who has the highest GPA between s[first] and s[last]; // if two or more students have the same highest GPA, return // the index of student with the smallest ID. // Parameters: ( In, In, In) int IndexOfTheStudent(const StudentType s[], int first, int last) { int index = first; for (int i = first + 1; i <= last; i++) { // How to compare two students on GPA and ID if (CompGPA_ID(s[i], s[index])) index = i; } return index; } -----

  9. Sorting Students on Two Fields // The function uses Selection Sorting method // to sort an array of struct StudentType on GPA in // ascending order and then on ID in descending order. // Parameters: ( InOut , In ) void SortStudentArray(StudentType s[], int size) { int index; for (int i = 0; i < size - 1; i++) { index = IndexOfTheStudent(s, i, size - 1); if (index != i) SwapInt(s[i], s[index]); } return; } -----

  10. Struct SectionType { int numStudents; StudentType students[30]; }; int main() { SectionType CS143; GetSection(CS143); cout << "The students before sorting: "; DisplaySection(CS143); SortStudentArray(CS143.students, CS143.numStudents); cout << "The students after sorting: "; DisplaySection(CS143); return 0; } -----

  11. Function Younger // The function compares two students: // It returns true if s1 younger than s2 // It returns false otherwise. // Parameters: ( In, In) bool Younger(const StudentType& s1, const StudentType& s2) { if ((s1.DOB.year > s2.DOB.year) || (s1.DOB.year == s2.DOB.year && s1.DOB.month > s2.DOB.month) || (s1.DOB.year == s2.DOB.year && s1.DOB.month == s2.DOB.month && s1.DOB.day > s2.DOB.day)) return true; else return false; ) -----

  12. Function After // The function compares two dates: // It returns true if date1 after date2 // It returns false otherwise. // Parameters: ( In, In) bool After(const TDate& date1, const TDate& date2) { if ((date1.year > date2.year) || (date1.year == date2.year && date1.month > date2.month) || (date1.year == date2.year && date1.month == date2.month && date1.day > date2.day)) return true; else return false; ) -----

  13. Function After // The function compares two dates: // It returns true if date1 after date2 // It returns false otherwise. // Parameters: ( In, In) bool After(const TDate& date1, const TDate& date2) { return ((date1.year > date2.year) || (date1.year == date2.year && date1.month > date2.month) || (date1.year == date2.year && date1.month == date2.month && date1.day > date2.day)); } -----

  14. Function Younger bool After(const TDate& date1, const TDate& date2); // The function compares two students: // It returns true if s1 younger than s2 // It returns false otherwise. // Parameters: ( In, In) bool Younger(const StudentType& s1, const StudentType& s2) { if (After(s1.DOB, s2.DOB)) return true; else return false; ) -----

  15. Function Younger bool After(const TDate& date1, const TDate& date2); // The function compares two students: // It returns true if s1 younger than s2 // It returns false otherwise. // Parameters: ( In, In) bool Younger(const StudentType& s1, const StudentType& s2) { return After(s1.DOB, s2.DOB); ) -----

  16. Other Sorting Algorithms • Bubble Sorting • Insertion Sorting • Merge Sorting • Heap Sorting • Quick Sorting • Others

  17. Quiz 9 – Part III • 2 points • Do it in HiC • Submit to HiC server as Quiz93 • Due Monday, by 5 PM -----

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