Question

Assume that you will be given a *.txt file, which in the same format of RandSource.txt (attached). The file has three numbers at each line. Numbers are separated with a space. All number are in the range of [0, 50]. The first two numbers indicate a range. The third one shows number of random numbers to be generated in the range of first two numbers. The range always given in first < second order. If not, raise an error.

For instance,

2 5 7  means that you need to generate 7 random numbers in the range of 2 - 5 (including 2 and 5).

You need to develop a complete C++ program to read each line from the .txt file and print the result on screen in a formatted way. The output format will be <first number> - <second number>: <random numbers > . For the above example, the output to screen should be

2 - 5: 6 5 4 6 3 7 5

The attached input file has,

3 6 8
2 19 10
4 12 4
1 6 0
7 4 3
0 8 3
10 9 8

Your program should generate this (or with different random numbers) output for this file

3 - 6: 5 4 3 5 6 3 4 5
2 - 19: 6 2 11 14 17 9 8 19 2 7
4 - 12: 5 4 10 9
1 - 6:                         // no output here since quantity is 0
7 - 4: error
0 - 8: 0 6 4
10 - 9: error

Note that your program should any number of lines in the file. You strictly assume that all numbers are in the range of [0,50].

Answer 1

#include <iostream>
#include<sstream>
#include<fstream>
#include<time.h>
#include<random>
using namespace std;

int main()
{
// Open file to read
fstream fileIn;
fileIn.open("RandSource.txt");

// Check if file exists, If not end the program
if(!fileIn)
{
cout<<"File cannot be opened"<<endl;
return 0;
}

srand(time(NULL));
string line = "";
int low,high,totalNum;

// Iterate the loop till the last line in file
while(getline(fileIn,line))
{
// Read through stringstream and then store each respective value to its variables
stringstream ss(line);
ss>>low>>high>>totalNum;

// Print low-high
cout<<low<<" - "<<high<<": ";

// If low>high, print error
if(low>high)
{
cout<<"error"<<endl;
}
else
{
// Generate random number between given range totalNum times
// and print it
for(int i = 1; i<=totalNum; i++)
{
int val = rand()%(high-low+1)+low;
cout<<val<<" ";
}
cout<<endl;
}

}
// Close the file
fileIn.close();
return 0;
}

OUTPUT