CODEWITHSUNDEEP
c++performanceconsole-applicationcoutdev-c++
Mark
Mark

Reputation: 73

How can I make cout faster?

Is there any way to make this run faster and still do the same thing? 

#include <iostream>

int box[80][20];

void drawbox()
{
    for(int y = 0; y < 20; y++)
    {
        for(int x = 0; x < 80; x++)
        {
            std::cout << char(box[x][y]);
        }
    }
}

int main(int argc, char* argv[])
{
    drawbox();
    return(0);
}

IDE: DEV C++ || OS: Windows

Upvotes: 6

Views: 2708

Answers (3)

Mateen Ulhaq
Mateen Ulhaq

Reputation: 27201

As Marc B said in the comments, putting the output into a string first should be faster:

int box[80][20];

void drawbox()
{
    std::string str = "";
    str.reserve(80 * 20);

    for(int y = 0; y < 20; y++)
    {
        for(int x = 0; x < 80; x++)
        {
            str += char(box[x][y]);
        }
    }

    std::cout << str << std::flush;
}

Upvotes: 4

TonyK
TonyK

Reputation: 17114

The obvious solution is to declare the box array differently:

char box[20][81];

Then you can cout a row at a time. If you can't do this for whatever reason, then there's no need to use std::string here -- a char array is faster:

char row[81] ; row[80] = 0 ;
for (int y = 0; y < 20; y++)
  {
  for (int x = 0 ; x < 80 ; x++)
    row[x] = char(box[x][y]) ;
  std::cout << row ;
  // Don't you want a newline here?
  }

Upvotes: 2

Ben Voigt
Ben Voigt

Reputation: 283684

Sure, use putchar from stdio.h.

Upvotes: 1

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