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LAB 2: C BASICSITS100: Computer and Programming Lab.

Section 1Instructor: Wirat Chinnan

TAs:

Ms. Sasirassamee Buavirat

Mr. Thanasan Tanhermhong (Tum)

Ms. Pattheera Panitsuk (Fon+)

Mr. Pongsate Tangseng

Mr. Chinorot Wangtragulsang

Mr. Kanin Assantachai (Ob)

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variable type

%c%d%d%ld%f%lf

printf() and scanf()

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printf()• printf() is for output

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scanf()• scanf() is for input. • Do not forget & in front of variable names.

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Float and Integer

d i

2.54 2

5.8 5

1.3 1

3.00 3

float d;int i;

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Print Integer with getting input from keyboard

#include <stdio.h>

int main(){ int n1; printf(“Enter a Number: “); scanf(“%d”,&n1); printf(“n1 = %d\n”, n1); return 0;}

Enter a Number: 10n1 = 10

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Print Integer with getting input from keyboard

#include <stdio.h>

int main(){ int n1,n2; printf(“Enter 1#: “); scanf(“%d”,&n1); printf(“Enter 2#: “); scanf(“%d”,&n2); printf(“output = %d %d\n”, n1,n2); return 0;}

Enter 1#: 10Enter 2#: 20output = 10 20

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Reads in two integer and prints out the result of the first number divided by the second number.

#include <stdio.h>

int main(){ int n1,n2, ans; printf(“Enter two numbers: ”); scanf(“%d %d”,&n1,&n2); ans = n1/n2; // mathematic expression printf(“Remainder = %d\n”, ans); return 0;} Enter two Numbers: 21 6

Remainder = 3

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Reads in two decimal and prints out the result of the first number divided by the second number.

#include <stdio.h>

int main(){ float n1,n2, ans; printf(“Enter two numbers: ”); scanf(“%f %f”,&n1,&n2); ans = n1/n2; printf(“Remainder = %f\n”, ans); return 0;} Enter two Numbers: 21 6

Remainder = 3.500000

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Reads in two integer and prints out the remainder of the first number divided by the second number.

#include <stdio.h>

int main(){ int n1,n2, ans; printf(“Enter two numbers: ”); scanf(“%d %d”,&n1,&n2); ans = n1%n2; // % means modulo operation printf(“Remainder = %d\n”, ans); return 0;}

Enter two Numbers: 22 6Remainder = 4

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Mathematical Functions• #include<math.h>• All of these functions require arguments in float and

return float

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Finds the square root of an input.

#include <stdio.h>#include <math.h>int main(){ float n1, ans; printf(“Enter a number: ”); scanf(“%f”,&n1); ans = sqrt(n1); printf(“square root = %f\n”, ans); return 0;}

Enter a number : 3square root = 1.732051

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Finds the power of an input.

#include <stdio.h>#include <math.h>

int main(){ int n1,n2, ans; printf(“Enter two numbers: ”); scanf(“%d %d”,&n1,&n2); ans = pow(n1,n2); printf(“n1 power n2 = %d\n”, ans); return 0;}

Enter two Numbers: 2 3n1 power n2 = 8

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To Do in Class• Exercise 1 - 5• Call your TA when you finished. • You may take a break • Be ready for the speed test at 15.00

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Speed Test• Speed test should be treated just like a real exam. • Rules:

• No talking. Be quiet.• No mobile phone.• No electronic devices other than your PC• No Internet• No cheating

• Cheating will result in a severe penalty

• TAs will not help you (except when your PC crashes).• Time allowed: 45 minutes.

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Speed Test Instruction• Write your name on the question sheet.• Create all workspace on your ‘Desktop’ and set

workspace’s name follow: Sx_ID_Gx

Example : S1_5322793303_G1

(for Section 1 ID 5322793303 Group 1)

Example : S1_5322793303_G2

(for Section 1 ID 5322793303 Group 2) • When you finished

• Raise your hand to signal the assigned TA• TA grades your work• Quietly leave the room

• DO NOT bring the question sheet out. Leave it on your table.