Lecture 8 Code Snippets

Slide 17

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>

void sub(double a , double b)
{
    double res = a - b;
    printf("Sub of %f and %f is %f\n", a, b, res);
}

int main()
{
    double d1 = 10, d2 = 20;
    sub(56.0, 6.0); 
    sub(d1, d2); 
    sub(d1, d2 + d2);
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 22

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
//wrong version
void add(double a, double b, double res)
{
    res = a + b;
    return;

}
int main()
{
    double d1 = 10.1, d2 = 20.2;
    double result = 0;
    add(56.0, 6.7, result);
    printf("result = %f\n", result);
    add(d1, d2, result);
    printf("result = %f\n", result);
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 23

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>

int b(int i)
{
    return i;
}

int c(int j)
{
    return j;
}

int a (int i, int j)
{
    b(i);
    c(j);
    return 0;
}

int main()
{
    a(3,5);
    return 0;
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 27

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
double fabs(double x)
{
    if(x<=0)
        return -x;
    return x;
}
int main()
{
    double d = -10;
    double b;
    b = fabs(d);
    printf("%lf\n", b);
    printf("%lf\n", fabs(-2 * b));
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 28

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
double my_fabs( double x)
{
    double res;
    if(x >= 0)
        res = x;
    else
        res = -x;

    return res;

}

int main()
{
    double d = -10;
    double b;
    b = my_fabs(d);
    printf("b = %lf\n", b);
    b = my_fabs(-2 * d);
    printf("b = %lf\n", b);
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 31

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>

f1(a)
{
    printf("a = %d\n", a);
    return a / 2;
}

f2(int a)
{
    printf("a = %d\n", a);
    return a / 2;
}

f3(float a)
{
    printf("a = %f\n", a);
    return a / 2;
}

int main()
{
    printf("%d\n", f1(10.5));
    printf("%d\n", f2(10.5));
    printf("%d\n", f3(10.5));
    return 0;
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 33

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
#define PRINT_INT(x) printf("%d\n", x); \
                    printf("================\n");

inline int gcd(int a, int b)
{
    int temp;
    while(b != 0)
    {
        temp = a%b;
        a = b;
        b = temp;
    }

    return a;
}

int main()
{
    int i = 20, j = 35, g;
    g = gcd(j, i);
    printf("GCD of %d and %d = ", i , j);
    PRINT_INT(g);
    g = gcd(j, i);
    printf("GCD of %d and %d = ", j , i);
    PRINT_INT(g);
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 37

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
int main()
{
    int i;
    for(i = 1; i <= 10; i++){
    int number;
    printf("Enter %d-th number: ", i);
    scanf("%d", &number);
    if((number % 2) == 0)
    printf("Your number is even\n");
    else
    printf("Your number is odd\n");
    }
    printf("The last number is %d\n", number);
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 41

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
int main()
{
    int j = 20, i = 10, k = 0;
    printf("outer i = %d, %d\n", i, j);
    while(k != 1)
    {
    int i = 100;
    j = 200;
    printf("inner i = %d, %d\n", i, j);
    k++;
    }
    printf("outer i = %d, %d\n", i, j);
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 44

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
int i, j;
float f;
void func(void)
{
    printf("i = %d\n", i);
    printf("f = %f\n", f);
    i = 20;
}
void f1()
{
    printf("%d", i);
}

int main()
{
    f = 1000;
    func();
    f1();
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 45

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
double x;

void fabs(void)
{
    x = (x>=0) ? x : -x;
}

int main()
{
    double b, d = -10;
    x = d;
    fabs();
    b = x;
    printf("b  = %f\n", b);
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 50

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
int x=50;
int main()
{
    int x=100;
    {
        extern int x;
        printf("x= %d\n",x);
    }

printf("x= %d\n",x);
return 0;
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 57

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
int i = 10, j = 20;

void print(void)
{
    printf("i = %d, j = %d\n", i , j);
}

int main()
{
    extern int i;
    int j;

    print();
    i = 1000;
    j = 2000;
    print();
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 58

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
int i;
void func(void)
{
    int j;
    printf("i = %d\n", i);
    printf("j = %d\n", j);
    i= 20;
}

int main()
{
    func();
    func();
    i = 30;
    func();
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 59

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>

void func(void)
{
    int j;
    static int i = 10;
    printf("i = %d\n", i);
    printf("j = %d\n", j);
    i = 20;
}
int main()
{
    func();
    func();
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 60

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
void func(void)
{
    int j;
    static int i;
    printf("i = %d \n", i);
    printf("j = %d \n", j);
    i = 20;
}

int main()
{
    func();
    func();
    i = 30;
    func();
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 63

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
int main()
{
    int i;
    for(i = 0; i < 5; i++)
    {
        int j;
        if(i)
    {
        printf("&j = %p, j = %d\n",&j, j);
        j++;
    }
    else
        j = i;
    }
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 64

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
int main()
{
    int i;
    for(i = 0; i < 5; i++)
    {
        int j[5 * i + 1];
        if(i)
        {
            printf("&j[0] = %p, j[0] = %d\n", &(j[0]), j[0]);
            j[0]++;
        }
        else
            j[0] = i;
   }
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 65

CC++CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
int main()
{
    int i;
    for(i = 0; i < 5; i++)
    {
        int j[5 * 3 + 1];
        if(i)
        {
            printf("&j[0] = %p, j[0] = %d\n", &(j[0]), j[0]);
            j[0]++;
        }
        else
            j[0] = i;
   }
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

Slide 67

/** By: Negin Eini-pour **/
#include <stdio.h>
#include <math.h>

int check_prime(int n)
{
    if( n<=1)
        return 0;
    if(n == 2 || n==3)
        return 1;
    for(int i = 3 ; i<=sqrt(n); i++)
        if(n % i == 0)
            return 0;

    return 1;
}

int next_prime(int n)
{
    if( n==2)
        return 3;

    do
    {
        n+=2;
    }while(check_prime(n) == 0);

    return n;
}

int check_goldbakh(int n)
{
    int i = 2;

    while(i <= n/2)
    {
        int j = n - i;
        if(check_prime(j))
            return 1;
        i = next_prime(i);
    }

    return 0;
}

int main()
{
    int n;
    scanf("%d", &n);

    printf("%s\n", check_goldbakh(n) ? "true" : "false");
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 78

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
int fact(int n)
{
    int res, tmp;
    if(n == 1)
        return 1;
    return n * fact(n - 1);  
}

int main()
{
    int i = 4; 
    printf("%d\n", fact(i));
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 85

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
int gcd(int a, int b)
{
    if(b == 0)
        return a;
    return gcd( b , a%b);
}

int main()
{
    printf("gcd(1, 10) = %d \n", gcd(1, 10));
    printf("gcd(10, 1) = %d \n", gcd(10, 1));
    printf("gcd(15, 100) = %d \n", gcd(15, 100));
    printf("gcd(100, 15) = %d \n", gcd(100, 15));
    printf("gcd(201, 27) = %d \n", gcd(201, 27)); 
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 86

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
int fibo(int n)
{
    if( n == 1 || n == 2)
        return 1;
    return fibo(n-1) + fibo(n-2);
}

int main()
{
    printf("fibo(1) = %d\n", fibo(1));
     printf("fibo(3) = %d\n", fibo(3));
     printf("fibo(5) = %d\n", fibo(5));
     printf("fibo(8) = %d\n", fibo(8));
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 87

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
void print_right_left(int n)
{
    if(n == 0)
        return;

    printf("%d", n % 10);
    print_right_left(n/10);
}

int main()
{
    printf("\n print_digit_right_left(123): ");
    print_right_left(123); 
    printf("\n print_digit_right_left(1000): ");
    print_right_left (1000);   
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 88

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
void print_left_right(int n)
{
    if(n == 0)
        return;
    print_left_right(n/10);
    printf("%d", n % 10);
}

int main()
{
    printf("\n print_digit_left_right(123): ");
    print_left_right(123); 
    printf("\n print_digit_left_right(1000): ");
    print_left_right (1000);   
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 89

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>

int max(int a, int b)
{
    return a>b ? a : b;
}

int find_max(int a[], int n)
{
    if(n == 1)
        return a[0];
    return max( a[n-1], find_max(a , n-1)); 
    /*
    a[]= {a,b,c,d}
     --> find {a,b,c,d} = max(d , find{a,b,c}) -->max(d,max(c ,max(b, a)))
    --> find {a,b,c}= max(c , find{a,b}) --> max(c ,max(b, a))
    --> find {a,b} = max(b , find{a}) --> max(b, a)
    --> find{a} = a
    */
}

int main()
{
    int arr[] = {10, 324, 450, 290, 150};
    int n = sizeof(arr)/sizeof(arr[0]);
    printf("Largest in given array is %d", find_max(arr, n));
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}

---

Slide 91

CC++

/** By: Negin Eini-pour **/
#include <stdio.h>
#include <stdbool.h>

bool is_even(int n);
bool is_odd(int n);

bool is_even(int n)
{
    if(n == 0)
        return true;
    if(n == 1)
        return false;
    else
        return is_odd(n - 1);
}

bool is_odd(int n)
{
    if(n == 0)
        return false;
    if(n == 1)
        return true;
    else
        return is_even(n - 1);
}

int main()
{
    printf("3-->%s, 4-->%s", is_odd(3) ? "odd" : "even", is_odd(4) ? "odd" : "even");
}

#include <iostream>

int main() {
    // Your code here
    return 0;
}