[HackerRank] Introduction in C

https://www.hackerrank.com/domains/c

Solve C Code Challenges

 

[1] Hello World in C

 

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

int main() 
{
	
    char s[100];
    scanf("%[^\n]%*c", &s);
  	
    printf("Hello, World!\n");
    printf("%s", *&s);
        
    return 0;
}

scanf("%[^\n]%*c", &s);

https://stackoverflow.com/questions/30065675/what-does-scanf-nc-mean

What does `scanf("%*[^\n]%*c")` mean?

 

[2] Playing With Characters

 

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

int main() 
{
    char ch;
    char s[20], sen[100];
    
    scanf("%c", &ch);
    scanf("%s", s);
    scanf("\n");
    scanf("%[^\n]%*c", sen);
    
    printf("%c\n", ch);
    printf("%s\n", s);
    printf("%s\n", sen);
    
    return 0;
}

 

[3] Sum and difference of two numbers.

 

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

int main()
{
	
    int num1, num2;
    float num3, num4;
    
    scanf("%d %d", &num1, &num2);
    scanf("%f %f", &num3, &num4);
    
    printf("%d %d\n", num1+num2, num1-num2);
    printf("%.1f %.1f", num3+num4, num3-num4);
    
    return 0;
}

 

[4] Functions in C

 

#include <stdio.h>

int max_of_four(int a, int b, int c, int d){
    int max;
    
    max = (a>b)?a:b;
    max = (max>c)?max:c;
    max = (max>d)?max:d;
    
    return max;
}

int main() {
    int a, b, c, d;
    
    scanf("%d %d %d %d", &a, &b, &c, &d);
    int ans = max_of_four(a, b, c, d);
    printf("%d", ans);
    
    return 0;
}

 

[5] Pointers in C

 

#include <stdio.h>

void update(int *a,int *b) {
    *a += *b;
    *b = abs(*a - 2 * *b);
}

int main() {
    int a, b;
    int *pa = &a, *pb = &b;
    
    scanf("%d %d", &a, &b);
    update(pa, pb);
    printf("%d\n%d", a, b);

    return 0;
}​