String help!!

[kenneth_888]

i wrote this programme that will read a sentence from standard input and output the sentence with spacing corrected and letters corrected for capitalization. in other words if the input sentence has spaces between words composed of more than one blank in the ouput sentence these spaces should be compressed into onto one single blank. the sentence should start with uppercase letter and then contain no other uppercase letter.
But im not able to store the whole sentence?only one word is converted.

#include <iostream>
using namespace std;

int main()
{
   
   
    string str;
   cin >> str;
    cout << "Before: " << str << endl;

    str[0] = toupper(str[0]);   // Capitalize first letter
    if (str[str.size()-1] != '.') str += '.';   // Add period at end of string

    for(size_t i = 1; i < str.size(); i++)
        str = tolower(str);   // Lower case all letters other than the first.

    cout << "After : " << str;

    return 0;

}

[MacGyver]

cin is only reading the first word. You have to use one of the getline() functions.

[kenneth_888]

i did this now but still problems??i duno where the problem is??

#include<iostream>
#include<string>
using namespace std;

int main()
{
    
	
	string str;
	getline(cin, str,'\n');
    cout << str << endl;

    str[0] = toupper(str[0]);   // Capitalize first letter
    if (str[str.size()-1] != '.') str += '.';   // Add period at end of string

    for(size_t i = 1; i < str.size(); i++)
        str = tolower(str);   // Lower case all letters other than the first.

    cout << "After : " << str;

    return 0;

}

[MacGyver]

str = tolower(str);   // Lower case all letters other than the first.

 In function `int main()':
17: error: no matching function for call to `tolower(std::string&)'
note: candidates are: int tolower(int)

Change to:

str[i] = tolower(str[i]);