Decision making statements (if else) in C programing (examples)

Decision making statements in C

C program calculate roots (both real and imaginary) of a quadratic equation.

#include <stdio.h>
#include <math.h>
main()	{
	float a, b, c, root1, root2, rp, ip;
	printf("Enter the coefficients: \n");
	printf("a: ");
	scanf("%f",&a);
	printf("b: ");
	scanf("%f",&b);
	printf("c: ");
	scanf("%f",&c);
	if(b*b-4*a*c>0){
		root1=(-b+sqrt((b*b)-(4*a*c)));
		root2=(-b-sqrt(b*b-4*a*c));
		printf("x1 = %0.2f \nx2 = %0.2f",root1, root2);
	}else if(b*b-4*a*c==0){
		root1=root2=-b/(2*a);
		printf("x1 = x2 = %0.2f",root1);
	}else{
		rp=-b/(2*a);
		ip=sqrt(4*a*c-b*b);
		printf("x1 = %0.2f+%0.2fi \nx2= %0.1f-%0.1fi",rp,ip,rp,ip);
	}
	return 0;
}   

C program calculate largest number among three entered by user.

// Using if else statements
#include <stdio.h>
main()	{
	int a, b, c;
	printf("Enter three numbers: ");
	scanf("%d %d %d",&a, &b, &c);
	if(a>b){
		if(a>c){
			printf("Largest: %d",a);
		}else{
			printf("Largest; %d",c);
		}
	}else{
		if(b>c){
			printf("Largest; %d",b);
		}else{
			printf("Largest; %d",c);
		}
	}
	return 0;
}  

// Using conditional operator (single line code)
#include <stdio.h>
main(){
	int a, b, c, largest;
	printf("Enter three numbers: ");
	scanf("%d %d %d",&a, &b, &c);
	largest = (a>b?a:b)>c?(a>b?a:b):c;
	printf("Largest = %d",largest);
	return 0;
}