week5

1. Week 5
Practice

2. Function
return-value-type function-name(parameter-list) {
statement
return return-value;
}

3. Function - Sum
a+b
b
a
• Function name is sum
• a and b are integer

4. Function - Sum
a+b
b
a
Parameter

5. Function - Sum
a+b
b
a
Return value

6. Function - Sum
int sum(int a, int b) {
return a+b;
}
a+b
b
a

7. Function - Sum
#include <stdio.h>
int sum(int a, int b);
int main() {
printf(“%d”, sum(2, 3));
return 0;
}
int sum(int a, int b) {
return a+b;
}

8. Function - Sum
#include <stdio.h>
int sum(int a, int b);
int main() {
printf(“%d”, sum(2, 3));
return 0;
}
int sum(int a, int b) {
return a+b;
}

9. Function - Sum
#include <stdio.h>
int sum(int a, int b);
int main() {
printf(“%d”, sum(2, 3));
return 0;
}
int sum(int a, int b) {
return a+b;
}

10. Function – 4 Sum
a+b+c+d
c
b a
d

11. Function – 4 Sum
a+b+c+d
c+d
a+b
d
c
b
a

12. Function – 4 Sum
#include <stdio.h>
int sum(int a, int b);
int main() {
printf(“%d”, sum(sum(1, 2), sum(3, 4));
return 0;
}
int sum(int a, int b) {
return a+b;
}

13. Math Library Functions

15. undefined reference to '<FUNC>'
collect2: ld returned 1 exit status
Open ‘Build Configuration’
menu

16. undefined reference to '<FUNC>'
collect2: ld returned 1 exit status
Append –lm and apply

17. Practice 1
𝑁 = 𝑛 + 𝛼
𝑛 𝑖𝑠 𝑖𝑛𝑡𝑒𝑔𝑒𝑟, 0 ≤ 𝛼 < 1
Input
Real number 𝑁 (𝑡𝑤𝑜 𝑑𝑒𝑐𝑖𝑚𝑎𝑙 𝑝𝑙𝑎𝑐𝑒𝑠)
Output
𝑁 = 𝑛 + 𝛼 (𝑁, 𝛼 𝑡𝑤𝑜 𝑑𝑒𝑐𝑖𝑚𝑎𝑙 𝑝𝑙𝑎𝑐𝑒𝑠)
*DO NOT UES if
Ex) Ex)
5.43 0
5.43=5+0.43 0.00=0+0.00

18. Practice 2
𝑎𝑥2 + 𝑏𝑥 + 𝑐 = 0
Input
Real number 𝑎, 𝑏, 𝑐 (𝑎 ≠ 0, 𝑏2
− 4𝑎𝑐 > 0)
Output
Find the value of 𝑥 (𝑡𝑤𝑜 𝑑𝑒𝑐𝑖𝑚𝑎𝑙 𝑝𝑙𝑎𝑐𝑒𝑠)
Ex) Ex)
1 5 3 4.8 15.9 3.2
-0.70 -4.30 -0.22 -3.10

19. Practice 3
a mod b = 𝑟0
b mod 𝑟0 = 𝑟1
𝑟0 mod 𝑟1 = 𝑟2
…
𝑟𝑛−1 mod 𝑟𝑛 = 0
𝑟𝑛 is the greatest common divisor (gcd) of a and b
For example,
1071 mod 462 = 147
462 mod 147 = 21
147 mod 21 = 0
21 is the greatest common divisor (gcd) of 1071 and 462

20. Practice 3
Input
Natural number a, b
Output
GCD of a and b
*Create functions: gcd
Ex) Ex) Ex)
1071 462 30 8 24 56
21 2 8

21. Homework - Continued fractions
𝑚
𝑛
= 𝑎0 +
1
𝑎1 +
1
𝑎2 +
1
⋱ +
1
𝑎 𝑛
For example,
12
5
= 2 +
2
5
= 2 +
1
5
2
= 2 +
1
2 +
1
2

22. Homework - Continued fractions
1071
462
= 2 +
1
3 +
1
7
3
4
= 0 +
1
1 +
1
3
43
23
= 1 +
1
1 +
1
6 +
1
1 +
1
2

23. Homework - Continued fractions
Input
Natural number m, n
Output
𝑎0, 𝑎1, 𝑎2, ⋯ , 𝑎 𝑛
Ex) Ex) Ex)
1071 462 1234 2345 3 4
2 3 7 0 1 1 9 30 1 3 0 1 3