CODEWITHSUNDEEP
c++algorithm
Michael
Michael

Reputation: 21

Keeping track of which is the smallest and which is the largest value so far in a loop

could you please help me with solving simple problem? I am very fresh with C++ and learning from book "Programming: Principles and Practice Using C++ by Bjarne Stroustrup". I have never learnt C++ before so I am not familiar with many useful features. The drill says:

"6. Now change the body of the loop so that it reads just one double each time around. Define two variables to keep track of which is the smallest and which is the largest value you have seen so far. Each time through the loop write out the value entered. If it’s the smallest so far, write the smallest so far after the number. If it is the largest so far, write the largest so far after the number"

I do not know how to do this correctly without using vector. Here is my code:

#include "C:/std_lib_facilities.h"

int main()
{
    double a, b,differ=0;
    char c=' ';
    cout << "Enter two values: \n";
    while (c != '|' && cin >> a >> b )
    {
        if (a > b)
        {
            cout << "The smaller value is: "<< b << " and the larger value is: " << a << "\n \n";
            differ = a - b;
            if (differ < 1.0 / 100)
                cout << "Numbers are almost equal\n\n";
        }
        else if (a < b)
        {
            cout << "The smaller value is: " << a << " and the larger value is: " << b << "\n \n";
            differ = b - a;
            if (differ < 1.0 / 100)
                cout << "Numbers are almost equal\n\n";
        }
        else
        {
            cout << "These values are equal!\n";
        }
        cout << "Enter a character | to break loop: \n";
        cin >> c;
    }
    cout << "You have exited the loop.\n";
    keep_window_open();
}

And here are previous steps, these I have solved with code above:

  1. Write a program that consists of a while-loop that (each time around the loop) reads in two ints and then prints them. Exit the program when a terminating '|' is entered.
    1. Change the program to write out the smaller value is: followed by the smaller of the numbers and the larger value is: followed by the larger value.
    2. Augment the program so that it writes the line the numbers are equal (only) if they are equal.
    3. Change the program so that it uses doubles instead of ints.
    4. Change the program so that it writes out the numbers are almost equal after writing out which is the larger and the smaller if the two numbers differ by less than 1.0/100.

Could you give me some hint how to do step 6.? I had some ideas but none of them worked..

Here is new code:

#include "C:/std_lib_facilities.h"

int main()
{
    double smallestSoFar = std::numeric_limits<double>::max();
    double largestSoFar = std::numeric_limits<double>::min();
    double a,differ=0;
    char c=' ';
    cout << "Enter value: \n";

    while (c != '|' && cin >> a)
    {
        if (a > largestSoFar)
        {
            largestSoFar = a; 
            cout <<"Largest so far is: "<< largestSoFar << endl;
        }
        else if (a < smallestSoFar)
        {
            smallestSoFar = a;
            cout <<"Smallest so far is: "<< smallestSoFar << endl;
        }
        else if(smallestSoFar >= a && a<=largestSoFar)
            cout << a << endl;
        cout << "Enter a character | to break loop: \n";
        cin >> c;
    }
    cout << "You have exited the loop.\n";
    keep_window_open();
}

Upvotes: 0

Views: 2779

Answers (3)

EOF
EOF

Reputation: 1

Based on the knowledge that you are suppose to know at the current stage for the this assignment. The code should go something like this:

#include < iostream>
#include < cstdlib>

 int main() {

 double num_1 = 0;
 double num_2 = 0;
 double largest = 0;
 double smallest = 0;

 bool condition1 = true;

 while (true) {

    std::cin >> num_1;

    if (num_1 > largest){
        largest = num_1;
    }
    else if (num_1 < smallest) {
        smallest = num_1;
    }
    
    std::cout << "The largest so far: " << largest << std::endl;

    std::cin >> num_2;
    
    if (condition1) {
        smallest = largest;
        condition1 = false;
    }

    if (num_2 < smallest) {
        smallest = num_2;
    }
    else if (num_2 > largest) {
        largest = num_2;
    }
    
    std::cout << "The smallest so far: " << smallest << std::endl;
}

system("pause");
return 0;
}

Upvotes: 0

Kevin Davis
Kevin Davis

Reputation: 1

double large = 0;
double small = 0;

double input;
int counter = 0;

while (counter < 5) {
    cin >> input;
    cout <<"Large value: "<< large << '\t' <<"Small value: "<< small\
        << '\t' <<"Input value: "<< input << '\n';
    if (input < small) {
        cout << "The smallest value is " << input<<\
            "\nthe largest value is "<< large<<'\n';
        small = input;
    }

    else if (input > small&& input < large) {
        cout << "The smallest value is " << small << \
            "\nthe largest value is " << large<<'\n';
    }
    else if (input > small&& input > large) {
        cout << "The smallest value is " << small << \
            "\nthe largest value is " << input << '\n';
        large = input;
    }
    counter += 1;

Upvotes: -1

Sergey Kalinichenko
Sergey Kalinichenko

Reputation: 726639

I do not know how to do this correctly without using vector.

You do not need vector for this. The description correctly says that two variables would be sufficient:

// Declare these variables before the loop
double smallestSoFar = std::numeric_limits<double>::max();
double largestSoFar = std::numeric_limits<double>::min();

Modify your loop to read into a, not into both a and b. Check the newly entered value against smallestSoFar and largestSoFar, do the printing, and re-assign smallest and largest as necessary. Note that the first time around you should see both printouts - for largest so far and for smallest so far.

Upvotes: 3

Related Questions