#include <stdio.h>
#include <math.h>
#include <stdlib.h>
long factorial( int n)
{
int i, mul;
mul=1;
for (i=1; i<=n; i++)
mul = mul*i;
return(mul);
}
int main()
{
char choices;
printf("1. Convert decimal to binary
");
printf("2. Compute square root n times
");
printf("3. Solve a quadratic equation
");
printf("4. Print something fun
");
printf("q. Quit the program
");
printf("Your choice is ");
scanf("%c", &choices);
if( choices == '1')
{
int bin, dec, inverst, remain;
printf("enter a decimal number :");
scanf("%d", &dec);
bin = 0;
inverst=1;
while(dec>0)
{
remain = dec%2;
bin = bin + inverst*remain;
inverst = inverst* 10;
dec = dec/2;
}
printf("<bin>=%d

",bin);
getchar();
}
else if ( choices == '2')
{
int m, n, c;
float t;
printf("Compute square root
");
printf("Please input number m: ");
scanf("%d", &m);
printf("Please input square root n times: ");
scanf("%d", &n);
t = 0;
do
{
for (c=1; c<=n; c++)
{
t = sqrt (t + m);
}
printf("t is %2f
", t);
}
while (n<0 || n>5);
getchar();
}
else if ( choices == '3')
{
float a, b, c, delta, x1, x2;
printf("The form of the quadratic equation is ax2 + bx + c = 0
");
printf("Input a = ");
scanf("%f", &a);
printf("Input b = ");
scanf("%f", &b);
printf("Input c = ");
scanf("%f", &c);
if (a==0)
printf("This is not the quadratic equation
Please check again
");
else
{
delta = b*b-4*a*c;
if(delta < 0 )
printf("The equation has no solution
");
else if (delta == 0 )
printf("The solution of the equation is %.2f
", (-b)/(2*a));
else
x1 = (-b - sqrt(delta))/(2*a);
scanf("%f", &x1);
x2 = (-b + sqrt(delta))/(2*a);
scanf("%f", &x2);
printf("The solution of the equation includes
");
printf("x1 = %.2f
", x1);
printf("x2 = %.2f
", x2);
}
getchar();
}
else if (choices == '4')
{
long factorial(int), num;
int A, B, C;
char ch, asc;
do
{
printf("Enter the number of row: ");
scanf("%d", &B);
}
while(B<1 || B>5);
printf("Print a pascal triangle of n rows
");
for(A=0; A<B; A++)
{
for(C=1; C<=B-A; C++)
{
printf(" ");
}
for(C=0;C<=A;C++)
{
num = factorial(A)/(factorial(C)*factorial(A-C));
printf("%ld ", num);
}
printf("
");
}
printf("printf a character triangle
");
for(A=0; A<=B; A++)
{
asc = A+64;
for(C=0; C<=B-A; C++)
{
printf(" ");
}
for(ch='A';ch<=asc; ch++)
{
printf("%C", ch);
}
for(ch=asc-1; ch>='A'; ch--)
{
printf("%C", ch);
}
printf("
");
}
getchar();
}
else if (choices == 'q')
{
exit(0);
}
else
{
printf("You just have 5 options : 1, 2, 3, 4 and q
Check again please
");
}
}

View more random threads: