From 077f0cd67295aca6aa0dd0cc80a78237e693095d Mon Sep 17 00:00:00 2001
From: Paul Weng <paulweng@Pauls-MacBook-Air.local>
Date: Thu, 9 Jul 2020 09:52:21 +0800
Subject: [PATCH] dynamic resizing demo

---
 L19-Dynamic-Resizing/1-Inc/IntSet.cpp    | 86 ++++++++++++++++++++++++
 L19-Dynamic-Resizing/1-Inc/IntSet.h      | 52 ++++++++++++++
 L19-Dynamic-Resizing/1-Inc/Makefile      | 34 ++++++++++
 L19-Dynamic-Resizing/1-Inc/main.cpp      | 22 ++++++
 L19-Dynamic-Resizing/2-Double/IntSet.cpp | 86 ++++++++++++++++++++++++
 L19-Dynamic-Resizing/2-Double/IntSet.h   | 52 ++++++++++++++
 L19-Dynamic-Resizing/2-Double/Makefile   | 34 ++++++++++
 L19-Dynamic-Resizing/2-Double/main.cpp   | 22 ++++++
 8 files changed, 388 insertions(+)
 create mode 100644 L19-Dynamic-Resizing/1-Inc/IntSet.cpp
 create mode 100644 L19-Dynamic-Resizing/1-Inc/IntSet.h
 create mode 100644 L19-Dynamic-Resizing/1-Inc/Makefile
 create mode 100644 L19-Dynamic-Resizing/1-Inc/main.cpp
 create mode 100644 L19-Dynamic-Resizing/2-Double/IntSet.cpp
 create mode 100644 L19-Dynamic-Resizing/2-Double/IntSet.h
 create mode 100644 L19-Dynamic-Resizing/2-Double/Makefile
 create mode 100644 L19-Dynamic-Resizing/2-Double/main.cpp

diff --git a/L19-Dynamic-Resizing/1-Inc/IntSet.cpp b/L19-Dynamic-Resizing/1-Inc/IntSet.cpp
new file mode 100644
index 0000000..d7978bc
--- /dev/null
+++ b/L19-Dynamic-Resizing/1-Inc/IntSet.cpp
@@ -0,0 +1,86 @@
+#include "IntSet.h"
+#include <iostream>
+
+using namespace std;
+
+IntSet::IntSet(int size): elts(new int[size]),
+    sizeElts(size), numElts(0){
+}
+
+IntSet::IntSet(const IntSet &is): elts(NULL), sizeElts(0), numElts(0){
+    cout << "Copy constructor\n";
+    copyFrom(is);
+}
+
+IntSet& IntSet::operator= (const IntSet &is){
+    if(this != &is)
+        copyFrom(is);
+    return *this;
+}
+
+IntSet::~IntSet(){
+    delete[] elts;
+}
+
+int IntSet::indexOf(int v){
+    for (int i = 0; i < numElts; i++){
+        if (elts[i] == v)
+            return i;
+    }
+    return sizeElts;
+}
+
+void IntSet::copyFrom(const IntSet &is){
+    if (is.sizeElts != sizeElts){ // Resize array
+        delete[] elts;
+        sizeElts = is.sizeElts;
+        elts = new int[sizeElts];
+    }
+    // Copy array
+    for (int i = 0; i < is.sizeElts; i++){ 
+        elts[i] = is.elts[i];
+    }
+    // Establish numElts invariant
+    numElts = is.numElts; 
+}
+
+void IntSet::grow(){
+    int *tmp = new int[sizeElts + 1];
+    for (int i = 0; i < numElts; i++) {
+        tmp[i] = elts[i];
+    }
+    delete [] elts;
+    elts = tmp;
+    sizeElts += 1;
+}
+
+int IntSet::size(){
+  return numElts;
+}
+
+bool IntSet::query(int v){
+  return (indexOf(v) != sizeElts);
+}
+
+void IntSet::insert(int v){
+    if (indexOf(v) == sizeElts){
+        if (numElts == sizeElts) 
+           grow(); 
+        elts[numElts++] = v;
+    }
+}
+
+void IntSet::remove(int v){
+    int victim = indexOf(v);
+    if (victim != sizeElts){
+        elts[victim] = elts[numElts-1];
+        numElts--;
+    }
+}
+
+void IntSet::print(){
+    for (int i = 0; i < numElts; i++){
+        cout << elts[i] << " " << flush;
+    }
+    cout << endl;
+}
diff --git a/L19-Dynamic-Resizing/1-Inc/IntSet.h b/L19-Dynamic-Resizing/1-Inc/IntSet.h
new file mode 100644
index 0000000..bf45e16
--- /dev/null
+++ b/L19-Dynamic-Resizing/1-Inc/IntSet.h
@@ -0,0 +1,52 @@
+#ifndef INTSET_H
+#define INTSET_H
+
+const int MAXELTS = 100;
+    
+class IntSet{
+// OVERVIEW: a mutable set of integers, |set| <= sizeElts
+    int *elts;    // pointer to dynamic array
+    int sizeElts; // capacity of array
+    int numElts;  // current occupancy
+
+    int indexOf(int v);
+    // EFFECTS: returns the index of v if it exists in the
+    //          array, sizeElts otherwise.
+
+    void copyFrom(const IntSet &is);
+    // MODIFIES: this
+    // EFFECTS:  copies is contents to this
+
+    void grow();
+    // MODIFIES: this
+    // EFFECTS:  enlarge the elts array, 
+    // 		 preserving current content
+public:
+    IntSet(int size = MAXELTS);  
+    // EFFECTS: create a set with specified capacity.
+    // It defaults to MAXELTS if not supplied.
+
+    IntSet(const IntSet &is); // copy constructor
+
+    IntSet& operator= (const IntSet& is); // assigment operator
+
+    ~IntSet(); // Destroy this IntSet
+
+    void insert(int v);
+    // MODIFIES: this
+    // EFFECTS: this = this + {v}
+    void remove(int v);
+    // MODIFIES: this
+    // EFFECTS: this = this - {v} if v is in this
+    //          throws int v otherwise.
+    bool query(int v);
+    // EFFECTS: returns true if v is in this, false otherwise.
+    int  size();
+    // EFFECTS: returns |this|.
+    void print();
+    // MODIFIES: cout
+    // EFFECTS: print out the integers contained in the set in
+    //          sequence.
+};
+
+#endif
diff --git a/L19-Dynamic-Resizing/1-Inc/Makefile b/L19-Dynamic-Resizing/1-Inc/Makefile
new file mode 100644
index 0000000..6c32488
--- /dev/null
+++ b/L19-Dynamic-Resizing/1-Inc/Makefile
@@ -0,0 +1,34 @@
+# variable definition
+
+CC = g++
+
+DEFS =
+LIBS =
+INCLUDES = #-I.
+HEADERS = #int_t.h int_impl.h
+MAINSRCS = main.cpp
+OTHSRCS = IntSet.cpp
+SRCS = $(MAINSRCS) $(OTHSRCS)
+OBJS = $(SRCS:.cpp=.o)
+TARGETS = $(MAINSRCS:.cpp=)
+
+CFLAGS = -g -Wall $(INCLUDES) $(DEFS)
+
+%.o: %.cpp
+	$(CC) $(CFLAGS) -o $@ -c $< 
+
+all: $(TARGETS)
+
+$(TARGETS): $(OBJS)
+	$(CC) $(CFLAGS) -o $(TARGETS) $(OBJS) $(LIBS)
+
+depend:
+	makedepend -Y $(INCLUDES) $(SRCS)
+
+memcheck: $(TARGETS)
+	valgrind --leak-check=full ./$(TARGETS)
+
+clean:
+	rm -f $(OBJS) $(TARGETS)
+
+.PHONY: all depend memcheck clean 
diff --git a/L19-Dynamic-Resizing/1-Inc/main.cpp b/L19-Dynamic-Resizing/1-Inc/main.cpp
new file mode 100644
index 0000000..8aedcb6
--- /dev/null
+++ b/L19-Dynamic-Resizing/1-Inc/main.cpp
@@ -0,0 +1,22 @@
+#include <iostream>
+#include <stdlib.h>
+#include <cstdlib>
+#include <ctime>
+#include "IntSet.h"
+
+using namespace std;
+
+int main(int argc, char *argv[]) {
+    int n = atoi(argv[1]);
+    srand(atoi(argv[2]));
+    IntSet s(1);
+
+    clock_t begin = clock();
+    for(int i=1; i<n; i++){
+    	s.insert(i);
+    }
+    clock_t end = clock();
+    cout << double(end - begin) / CLOCKS_PER_SEC << endl;
+
+    return 0;
+}
diff --git a/L19-Dynamic-Resizing/2-Double/IntSet.cpp b/L19-Dynamic-Resizing/2-Double/IntSet.cpp
new file mode 100644
index 0000000..cfae864
--- /dev/null
+++ b/L19-Dynamic-Resizing/2-Double/IntSet.cpp
@@ -0,0 +1,86 @@
+#include "IntSet.h"
+#include <iostream>
+
+using namespace std;
+
+IntSet::IntSet(int size): elts(new int[size]),
+    sizeElts(size), numElts(0){
+}
+
+IntSet::IntSet(const IntSet &is): elts(NULL), sizeElts(0), numElts(0){
+    cout << "Copy constructor\n";
+    copyFrom(is);
+}
+
+IntSet& IntSet::operator= (const IntSet &is){
+    if(this != &is)
+        copyFrom(is);
+    return *this;
+}
+
+IntSet::~IntSet(){
+    delete[] elts;
+}
+
+int IntSet::indexOf(int v){
+    for (int i = 0; i < numElts; i++){
+        if (elts[i] == v)
+            return i;
+    }
+    return sizeElts;
+}
+
+void IntSet::copyFrom(const IntSet &is){
+    if (is.sizeElts != sizeElts){ // Resize array
+        delete[] elts;
+        sizeElts = is.sizeElts;
+        elts = new int[sizeElts];
+    }
+    // Copy array
+    for (int i = 0; i < is.sizeElts; i++){ 
+        elts[i] = is.elts[i];
+    }
+    // Establish numElts invariant
+    numElts = is.numElts; 
+}
+
+void IntSet::grow(){
+    int *tmp = new int[sizeElts * 2];
+    for (int i = 0; i < numElts; i++) {
+        tmp[i] = elts[i];
+    }
+    delete [] elts;
+    elts = tmp;
+    sizeElts *= 2;
+}
+
+int IntSet::size(){
+  return numElts;
+}
+
+bool IntSet::query(int v){
+  return (indexOf(v) != sizeElts);
+}
+
+void IntSet::insert(int v){
+    if (indexOf(v) == sizeElts){
+        if (numElts == sizeElts) 
+           grow(); 
+        elts[numElts++] = v;
+    }
+}
+
+void IntSet::remove(int v){
+    int victim = indexOf(v);
+    if (victim != sizeElts){
+        elts[victim] = elts[numElts-1];
+        numElts--;
+    }
+}
+
+void IntSet::print(){
+    for (int i = 0; i < numElts; i++){
+        cout << elts[i] << " " << flush;
+    }
+    cout << endl;
+}
diff --git a/L19-Dynamic-Resizing/2-Double/IntSet.h b/L19-Dynamic-Resizing/2-Double/IntSet.h
new file mode 100644
index 0000000..bf45e16
--- /dev/null
+++ b/L19-Dynamic-Resizing/2-Double/IntSet.h
@@ -0,0 +1,52 @@
+#ifndef INTSET_H
+#define INTSET_H
+
+const int MAXELTS = 100;
+    
+class IntSet{
+// OVERVIEW: a mutable set of integers, |set| <= sizeElts
+    int *elts;    // pointer to dynamic array
+    int sizeElts; // capacity of array
+    int numElts;  // current occupancy
+
+    int indexOf(int v);
+    // EFFECTS: returns the index of v if it exists in the
+    //          array, sizeElts otherwise.
+
+    void copyFrom(const IntSet &is);
+    // MODIFIES: this
+    // EFFECTS:  copies is contents to this
+
+    void grow();
+    // MODIFIES: this
+    // EFFECTS:  enlarge the elts array, 
+    // 		 preserving current content
+public:
+    IntSet(int size = MAXELTS);  
+    // EFFECTS: create a set with specified capacity.
+    // It defaults to MAXELTS if not supplied.
+
+    IntSet(const IntSet &is); // copy constructor
+
+    IntSet& operator= (const IntSet& is); // assigment operator
+
+    ~IntSet(); // Destroy this IntSet
+
+    void insert(int v);
+    // MODIFIES: this
+    // EFFECTS: this = this + {v}
+    void remove(int v);
+    // MODIFIES: this
+    // EFFECTS: this = this - {v} if v is in this
+    //          throws int v otherwise.
+    bool query(int v);
+    // EFFECTS: returns true if v is in this, false otherwise.
+    int  size();
+    // EFFECTS: returns |this|.
+    void print();
+    // MODIFIES: cout
+    // EFFECTS: print out the integers contained in the set in
+    //          sequence.
+};
+
+#endif
diff --git a/L19-Dynamic-Resizing/2-Double/Makefile b/L19-Dynamic-Resizing/2-Double/Makefile
new file mode 100644
index 0000000..6c32488
--- /dev/null
+++ b/L19-Dynamic-Resizing/2-Double/Makefile
@@ -0,0 +1,34 @@
+# variable definition
+
+CC = g++
+
+DEFS =
+LIBS =
+INCLUDES = #-I.
+HEADERS = #int_t.h int_impl.h
+MAINSRCS = main.cpp
+OTHSRCS = IntSet.cpp
+SRCS = $(MAINSRCS) $(OTHSRCS)
+OBJS = $(SRCS:.cpp=.o)
+TARGETS = $(MAINSRCS:.cpp=)
+
+CFLAGS = -g -Wall $(INCLUDES) $(DEFS)
+
+%.o: %.cpp
+	$(CC) $(CFLAGS) -o $@ -c $< 
+
+all: $(TARGETS)
+
+$(TARGETS): $(OBJS)
+	$(CC) $(CFLAGS) -o $(TARGETS) $(OBJS) $(LIBS)
+
+depend:
+	makedepend -Y $(INCLUDES) $(SRCS)
+
+memcheck: $(TARGETS)
+	valgrind --leak-check=full ./$(TARGETS)
+
+clean:
+	rm -f $(OBJS) $(TARGETS)
+
+.PHONY: all depend memcheck clean 
diff --git a/L19-Dynamic-Resizing/2-Double/main.cpp b/L19-Dynamic-Resizing/2-Double/main.cpp
new file mode 100644
index 0000000..8aedcb6
--- /dev/null
+++ b/L19-Dynamic-Resizing/2-Double/main.cpp
@@ -0,0 +1,22 @@
+#include <iostream>
+#include <stdlib.h>
+#include <cstdlib>
+#include <ctime>
+#include "IntSet.h"
+
+using namespace std;
+
+int main(int argc, char *argv[]) {
+    int n = atoi(argv[1]);
+    srand(atoi(argv[2]));
+    IntSet s(1);
+
+    clock_t begin = clock();
+    for(int i=1; i<n; i++){
+    	s.insert(i);
+    }
+    clock_t end = clock();
+    cout << double(end - begin) / CLOCKS_PER_SEC << endl;
+
+    return 0;
+}