Add debug print messages to lecture7 code

sdevikar · sdevikar · commit 2f09bdf97c5b · 2021-05-31T23:17:43.000-04:00
diff --git a/alexander_stepaniv/lectures/lecture7/code/binary_counter.h b/alexander_stepaniv/lectures/lecture7/code/binary_counter.h
@@ -12,58 +12,83 @@ class binary_counter
 
 public:
   // Constructor. Input arguments: op and zero.
-  binary_counter(const Op& op, const T& zero) :
-    op(op), zero(zero) {
-    counter.reserve(24); 
+  binary_counter(const Op &op, const T &zero) : op(op), zero(zero)
+  {
+    counter.reserve(24);
   }
 
+  void print()
+  {
+    auto first = counter.begin();
+    auto last = counter.end();
+
+    while (first != last)
+    {
+      auto it = *first;
+      std::cout << *it << ",";
+      ++first;
+    }
+    std::cout << std::endl;
+  }
   // add
-  void add(T x) {
+  void add(T x)
+  {
     x = add_to_counter(counter.begin(), counter.end(), op, zero, x);
-    if (x != zero) counter.push_back(x);
+    if (x != zero)
+      counter.push_back(x);
   }
 
   // reduce
   // returns: value of the counter
-  T reduce() {
+  T reduce()
+  {
     return reduce_counter(counter.begin(), counter.end(), op, zero);
   }
 };
 
 template <typename T, typename I, typename Op>
 // requires Op is BinaryOperation(T)
-// and Op is associative 
+// and Op is associative
 // and I is ForwardIterator and ValueType(I) == T
-T add_to_counter(I first, I last, Op op, const T& zero, T carry) {
-    // precondition: carry != zero
-    while (first != last) {
-        if (*first == zero) {
-            *first = carry;
-            return zero;
-        }
-        carry = op(*first, carry);
-        *first = zero;
-        ++first;
+T add_to_counter(I first, I last, Op op, const T &zero, T carry)
+{
+  // precondition: carry != zero
+  while (first != last)
+  {
+    if (*first == zero)
+    {
+      *first = carry;
+      std::cout << "add_to_counter returning carry: zero" << std::endl;
+      return zero;
     }
-    return carry;
+    carry = op(*first, carry);
+    *first = zero;
+    ++first;
+  }
+  std::cout << "add_to_counter returning carry: " << *carry << std::endl;
+  return carry;
 }
 
 template <typename T, typename I, typename Op>
 // requires Op is BinaryOperation(T)
-// and Op is associative 
+// and Op is associative
 // and I is ForwardIterator and ValueType(I) == T
-T reduce_counter(I first, I last, Op op, const T& zero) {
-    while (first != last && *first == zero) {
-        ++first;
-    }
-    if (first == last) return zero;
+T reduce_counter(I first, I last, Op op, const T &zero)
+{
+  while (first != last && *first == zero)
+  {
+    ++first;
+  }
+  if (first == last)
+    return zero;
 
-    T result = *first;
-    while (++first != last) {
-        if (*first != zero) {
-            result = op(*first, result);
-        }
+  T result = *first;
+  while (++first != last)
+  {
+    if (*first != zero)
+    {
+      result = op(*first, result);
     }
-    return result;
-}
-
+  }
+  return result;
+}
diff --git a/alexander_stepaniv/lectures/lecture7/code/min.cpp b/alexander_stepaniv/lectures/lecture7/code/min.cpp
@@ -7,36 +7,50 @@
 // - compares two iterators and returns the one
 //   pointing to the smallest element
 template <typename Compare>
-class min_op 
+class min_op
 {
 private:
   Compare cmp;
+
 public:
-  min_op(const Compare& cmp) : cmp(cmp) {}
+  min_op(const Compare &cmp) : cmp(cmp) {}
   template <typename I>
-  I operator()(const I& x, const I& y) {
+  I operator()(const I &x, const I &y)
+  {
+    // std::cout << "comparing: " << *x << "," << *y << std::endl;
     return cmp(*y, *x) ? y : x;
   }
 };
 
 template <typename I, typename Compare>
 // requires I is a ForwardIterator
 // and Compare is a StrictWeakOrdering on ValueType(I)
-I min_element_binary(I first, I last, Compare cmp) {
+I min_element_binary(I first, I last, Compare cmp)
+{
   binary_counter<I, min_op<Compare> > min_counter(min_op<Compare>(cmp), last);
-  while (first != last) min_counter.add(first++); 
+  while (first != last)
+  {
+    std::cout << "adding " << *first << std::endl;
+    min_counter.add(first++);
+    min_counter.print();
+  }
   return min_counter.reduce();
 }
 
-int main() {
+int main()
+{
 
-    // plugin whatever numbers you want to test with
-    int data[] = {9, 13, 7, 124, 32, 17, 8, 32, 237, 417, 41, 42, 13, 14, 15};
-    int* end = data + sizeof(data)/sizeof(int);
-    int* min = min_element_binary(data, end, std::less<int>());
-    if (min == end) {
-        std::cout << "No elements" << std::endl;
-    } else { 
-        std::cout << "Min is " << *min << std::endl;
-    }
+  // plugin whatever numbers you want to test with
+  // int data[] = {9, 13, 7, 124, 32, 17, 8, 32, 237, 417, 41, 42, 13, 14, 15};
+  int data[] = {11, 10, 19, 13, 18, 4, 15};
+  int *end = data + sizeof(data) / sizeof(int);
+  int *min = min_element_binary(data, end, std::less<int>());
+  if (min == end)
+  {
+    std::cout << "No elements" << std::endl;
+  }
+  else
+  {
+    std::cout << "Min is " << *min << std::endl;
+  }
 }
