Answer:
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main()
{
//First we declare string variables to store file names for input and output
string inputName;
string outputName;
string sentence;
// Then declare char variable to get current char
char ch;
//The following section will prompt theuser to enter the file names and read
cout << "Enter input file name:\n";
cin >> inputName;
cout << "Enter output file name:\n";
cin >> outputName;
//ignore newline character left inside keyboard buffer
cin.ignore();
//Next we define the input and output files to be opened
ifstream inputFile(inputName);
ofstream outputFile(outputName);
if(!inputFile && !outputFile){
cout << "Error while opening the files!\n";
cout << "Please try again!\n";
//end program immediately
return 0;
}
//Using this loop to get lines one by one, delimited by '.'
while(getline(inputFile, sentence, '.')){
//bool variable to store if we have already
//printed capital first letter
bool alreadyCapitalized = false;
//Using of for loop on all characters of sentence
for(int counter = 0; counter < sentence.length(); counter++){
//if not alphabetical character,
//so whitespace or newline, print as is
if(!isalpha(sentence[counter]))
outputFile << sentence[counter];
//Condition statement for if it is alphabetical and no capitalization has been done, print it as uppercase
if(!alreadyCapitalized && isalpha(sentence[counter])){
outputFile << (char)toupper(sentence[counter]);
alreadyCapitalized = true;
}
//otherwise print this condition as lowercase
else if(alreadyCapitalized)
outputFile << (char)tolower(sentence[counter]);
}
//Printing of the output sentence with period in the end
outputFile << ".";
}
//Closing the files
inputFile.close();
outputFile.close();
return 0;
}
