Standard I/O: iostream
Console Output (cout)
The cout object is used for outputting data to the standard output device (usually your screen). It is buffered and type-safe.
// Example of formatting with iomanip cout << right << setw(5) << 122; cout << setw(5) << 78 << '\n'; // Basic Types int num = 10; string str = "Hello, CPP!"; cout << "Result: " << num << " - " << str << endl;
Console Input (cin)
Used for getting input from the user. Note that cin stops reading at whitespace (space, tab, newline).
Pro Tip: getline()
To read a full line of text including spaces, use getline(cin, str).
string str;
// Reads until space
cin >> str;
// Reads whole line until enter
getline(cin, str);
// Reads until custom delimiter ('.')
getline(cin, str, '.');Error & Logging
cerr (Unbuffered)
Outputs immediately. Best for critical errors.
clog (Buffered)
Stores in buffer first. Best for non-critical logging.
Data Types & Limits
Understanding the limits of data types is crucial in Competitive Programming to avoid Overflow and Underflow.
int
double
float
char
bool
long long
short
unsigned int
How to check limits?
Modern C++ (limits)
#include <limits> cout << numeric_limits<int>::max();
Simpler (climits)
#include <climits> cout << INT_MAX;