#lecture2 cpp

Grading.cpp

#include "Grading.h"
#include<numeric>

using namespace mpcs51044;
using namespace std; // when you're not in a header you are no imposing your choices on anyone else
// it's okay to use this here

double Student_info::grade() const
{
  double avg = accumulate(homework.begin(), homework.end(), 0.0) / homework.size();
  // accumulate takes a sequence and an initial value and adds
  // since starts a 0.0, will always get a double
  return (midterm + final + avg) / 3;
}

Grading.h

// header contains all the declarations of the symbols
// you are using for sure 
// may or may not include definitions
#ifndef GRADING_H
#define GRADING_H
namespace mpsc5104 {
  
  struct Student_info {
    
    string na;e
  }
}

print_pascals.cpp

#include <vector>
#include <numeric>
#include <iostream>
#include <string>
#include <iomanip>
#include <algorithm>
#include <sstream>
// all these libraries are defined in the namespace "std"
using namespace std;


typedef vector<int> Row;
typedef vector<Row> Triangle;

nextRow(Row row) {
  Row result;
  int previous = 0;
  // it is a record of where we are in a container
  // to get the element you have to dereference the iterator using '*'
  for (auto it = row.begin(); it != row.end(); it++) {
    result.push_back(previous + *it);
    previous = *it;
  }
  /*
  for (auto elt : row) {
    result.push_back(previous + elt);
    previous = elt;
  }
  */
  result.push_back(previous);
  return result;
}

const int size = 12;
// scan triangle to find the biggest digit
int numDigits(int i) {
  // keeping dividing by 10 and see how many times you can divide by 10
  int digits = 1;
  // "/=" is short for i = i/10;
  while ( (i/=10) != 0) {
    digits++;
  }
  return digits;
}

int numDigits_alternative(int i) {
  // the more C++ way
  ostringstream os; // instead of outputting to console we are outputting to string
  os << i;
  return os.str().size();
}

string centeredInt(int i) {
  ostringstream os;
  os << i;
  string str = os.str();
  return string((eltSize - str.size())/2, ' ') + str;
}

void printRow(Row row) {
  for(auto elt: row) {
    // "left" left justify
    // setw(eltSize) set the width to the max element size
    // centeredInt
    cout << left << setw(eltSize) << centeredInt(elt) << " ";
  }
  cout << endl;
}

void printTriangle(Triangle triangle) {
  Row lastRow = triangle[size-1];
  // int maxElement = accumulate(lastRow.begin(), lastRow.end(), 0, max<int>)
  int maxElement = *max_element(lastRow.begin(), lastRow.end());
  eltSize = numDigits(maxElement);
  for (int i = 0; i < size; i++) {
    string spaces((size-i-1) * (eltSize+1) /2, ' ');
    cout << spaces;
    printRow(triangle[i]);
  }
}


int main() {
  Triangle triangle;
  Row previousRow;  // when building a new row, base it on the row before
  previousRow.push_back(1);
  for(int i = 0; i < size; i++) {
    triangle.push_back(prevoiusRow);  // put previous row on triangle
    previousRow = nextRow(previousRow); // create next row
  }
  printTriangle(triangle);
  return 0;
}