Question

C++ programming by Malik D. S. 7th edition

5-1: Programs model life

programs are models of processes that occur in life. iteration is no exception. look around and find examples of looping processes that you encounter outside of your programming class. for examples, consider the instructions on the back of your shampoo bottle. lather, rinse, repeat. or consider the instructions on the back of the cake mix box: stir 100 times or until batter is smooth. what other examples of loops can you find?

5-2: counting with loops

write a program that inputs a number greater than or equal to 0. the program should then count from 0 to the number inputted using a for-loop, a while-loop, and a do...while loop.

if the user's input is not greater than or equal to 0, display an error message and require the user to try again until they get it right.

5-3: vote tally continued

in assignment 4-4, had created a program to tally votes. the results of the vote are contained in the input file votes.dat.

modify your program to use a loop to read through and process each record in the file votes.dat. the program should summarize the vote data to include a total tally of "yes" and "no" votes, as well as a break-down of votes based on the voter's district. your program should work regardless of the number of records contained within the file.

Answer 1

1: other looping examples are - like opening laptop - press power button to on - eneter password - perform task - shut down -again press power button to on etc.

2.

 #include<iostream> using namespace std; int main() { int num; int count=0; //enter the number by for loop for(count=0;count<1;count++) { cin>>num; if(num<=0) { count=0; cout<<"error , please try again"<<endl; } else { cout<<"number input by for loop"<<endl; } } count=0; //enter the number by while loop while(count==0) { cin>>num; if(num<=0) { count=0; cout<<"error , please try again"<<endl; } else { count++; cout<<"number input by while loop"<<endl; } } count=0; //eneter the number by do while loop do { cin>> num; if(num<=0) { count=0; cout<<"error , please try again"<<endl; } else { count++; cout<<"number input by do while loop"<<endl; } } while(count==0); } 

3. although assignment 4.4 is not give here but as per my understanding this is related to file handling so i am giving soluting for file handling

since you had not specifies format of file so i had done only with yes and no count, you can manipulate it according if needed.

 #include <iostream> #include <string> #include <fstream> #include<vector> int main() { using namespace std; ifstream file("file.txt"); vector<string>arr; if(file.is_open()) { while(file.good()) { string s; file >>s; arr.push_back(s); } } int yes=0,no=0; for(int i=0;i<arr.size();i++) { if(arr[i]=="yes") { yes=yes+1; } else if(arr[i]=="no") { no=no+1; } } cout<<"count of yes "<<yes<<" and count of no "<<no<<endl; }