[CS50] Week 1 Section + Pset 1 : Mario-more

 

Section은 Lecture과 Pset 사이의 간극을 줄여주는 추가 강의 세션입니당

Pset 풀기 전에 이걸 듣고 했다면 더 쉬웠을까요.. 

아무튼 중요하다고 생각되는 부분들만 메모해놓겠음!!

 

 

 

1. Variable : name for some value that can change

int calls = 3;

int : (data) type  /  calls : name  /  3 : value  /  = : assignment operator

 

 

 

2. Data Types

-Why do we need to decide which data types to use?

: It would determine what we can make the variable do!

 

<Truncation>

int calls = 4;
calls += 1; 
calls -= 2;
calls *= 3;
calls /= 2;

-In this case, int calls = 4;

because we're storing it in integer!

(float calls = 4.5;)

 

 

 

3. Placeholder

int main(void)
{
   string first_name = get_string("What is your first name?");
   string last_name = get_string("What is your last name?");
   printf("Hello, %s %s\n", first_name, last_name);
}

 

=> There can be multiple placeholders if you need!

Ex) 5th line : %s  %s

 

 

 

4. While Loops

int j = 0;
while (j < 4)
{
   printf("#");
   j++;
}
printf("\n");

=> ####\n

 

 

 

5. For Loops

for (int j = 0; j < 4; j++);
{
   printf("#");
}
printf("\n");

=> ####\n

 

 

 

6. Loop in Loop (Don't be afraid to put loop in loop!)

for (int i = 0; i < 4; i++)
{
   for (int j = 0; j < 4; j++)
    {
      printf("#");
    }
    printf("\n");
}

=> ####\n

      ####\n

      ####\n

      ####\n

 

 

 

7. Mario (Pset 1)

#include <stdio.h>
#include <cs50.h>

//List Function Prototype at the top (because C reads from top to bottom)
void print_row(int length);

int main(void)
{
   int height = get_int ("Height: ");
   for (int i =0; i < height; i++)
   {
      print_row(i + 1); //get the input of height from the user and use my own function
   }
   
//Creating my own function called print_row
void print_row(int length)
{
   for (int i = 0; i < length; i++)
   {
      printf("#");
   }
   printf("\n");
}

 

★ You can create your own function (Here, for example, print_row())

    -> But remember to list that function prototype at the top so that C can read it from top to bottom

★ print_row (i + 1) : enables you to print something like this:

#

##

###

...

 

★ How  do we change it from left-lined to right-lined? Like this:

#                                    #

##              ->             ##

###                          ###

 

=> Let's look at the relationship between 4 variables (height, row, column, and space)

height	row	space	column
Ex) 4	0	3	1
	1	2	2
	2	1	3
	3	0	4

 

★ Space = height - row - 1

 

 

 

The result being like:

#include <stdio.h>

#include <cs50.h>

int main(void)

{

int height, row, column, space;

do

{

height = get_int ("Height: ");

}

while (height < 1);

for (row = 0; row < height; row++)

{

for (space = 0; space < height - row - 1; space++)

{

printf(" ");

}

for (column = 0; column < height - space; column++)

{

printf("#");

}

printf(" ");

for (column = 0; column < height - space; column++)

{

printf("#");

}

printf("\n");

}

}