some changes

CPlusPlus20ForProgrammers-master/examples/ch06/ex01.cpp

@@ -0,0 +1,16 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+int main (){
+    double matris[5][6];
+    int number_of_start = 10;
+    for(int row_counter=1; row_counter <= number_of_start ; row_counter++){
+        for(int star_counter=0; star_counter < row_counter ; star_counter++)
+            cout << '*';
+        cout << endl;
+    }
+
+    return 0;
+}

CPlusPlus20ForProgrammers-master/examples/ch06/fig06_12.cpp

@@ -10,6 +10,10 @@ T multiply(T x, T y) {
 }
 
 
+auto multiply_auto(auto x, auto y) {
+   return x * y;
+}
+
 int multiply_int(int x, int y) {
    return x * y;
 }
@@ -20,7 +24,7 @@ double f(double& x){
 }
 
 template <typename T, typename F, long unsigned int N>
-T integrate (std::array<T, N> x, F f){
+T integrate (std::array<T, N>& x, F f){
 	T tmp{T(0)};
 	for (auto s: x){
             tmp+= f(s);
@@ -31,10 +35,11 @@ T integrate (std::array<T, N> x, F f){
 
 auto integrate_auto (auto x, auto f){
         auto tmp{x[0]};
-	tmp = 0.0;
+	
         for (auto s: x){
             tmp+= f(s);
         }
+        tmp-=x[0];
         return tmp;
 }
 
@@ -43,7 +48,7 @@ typedef double (*FUNC)(double&);
 
 
 template <typename T, long unsigned int N>
-T integrate2 (std::array<T, N> x, FUNC f){
+T integrate_legacy (std::array<T, N> x, FUNC f){
         T tmp{T(0)};
         for (auto s: x){
             tmp+= f(s);
@@ -69,6 +74,8 @@ int main() {
 
    std::cout << "Product of integers: " <<  std::accumulate( std::begin(integers), std::end(integers), 1, multiply<int>) << "\n";
 
+  //std::cout << "Product of integers: " <<  std::accumulate( std::begin(integers), std::end(integers), 1, multiply_auto) << "\n";
+
    std::cout << "Product of integers: " <<  std::accumulate( integers.cbegin(), integers.cend(), 1, multiply<int>) << "\n";
 
    std::cout << "Product of integers with a lambda: " << std::accumulate(std::begin(integers), std::end(integers), 1, multiply_lambda) << "\n";
@@ -77,9 +84,9 @@ int main() {
 
    std::cout << "Product of integers with a lambda: " << std::accumulate(std::begin(floats), std::end(floats), 1, multiply_lambda) << "\n";
 
-   std::cout << "Integration2  template  " << integrate2(floats, f) << "\n";
+   std::cout << "Integration2  template  " << integrate_legacy(floats, f_lambda) << "\n";
 
-   std::cout << "Integration  full  template  " << integrate(floats, f_lambda) << "\n";
+   std::cout << "Integration  full  template  " << integrate(floats, f) << "\n";
 
    std::cout << "Integration  auto          " << integrate_auto(floats, f_lambda) << "\n";
 

CPlusPlus20ForProgrammers-master/examples/ch06/histogram.cpp

@@ -25,12 +25,12 @@ int main() {
    double lower_bound = 0;
    std::uniform_real_distribution<double> randomReal{lower_bound, upper_bound};
 
-   constexpr size_t N{10};
+   constexpr size_t N{4};
    double del {(upper_bound-lower_bound)/N};
    std::array<double, N> histogram{};
 
    // roll die 60,000 times; use die value as frequency index
-   for (int roll{1}; roll <= 60'000; ++roll) {
+   for (int roll{1}; roll <= 6000; ++roll) {
 	   double val{ randomReal(engine)};
 	   accumulate<N>(histogram, val, lower_bound, upper_bound);
    }