C language

Diamond Program (with '*')

#include
#include
#include
void main(void)
{int a=9;
clrscr();
for(int l=1;l<=5;l++)
{
for(int m=1;m<=5-l;m++){printf(" ");}
for(int n=1;n<=(2*l)-1;n++){printf("*");}
printf("\n");
}
for(int i=0;i<=5;i++)
{
a=a-2;
for(int j=0;j<=i;j++){printf(" ");}
for(int k=a;k>0 ;k--){printf("*");}
printf("\n");
}
getche();
}

Diamond Program (with 'digits') 

#include
#include
#include
void main(void)
{int a=9;
clrscr();
for(int l=1;l<=5;l++)
{
for(int m=1;m<=5-l;m++){printf(" ");}
for(int n=1;n<=(2*l)-1;n++){printf("%d",l);}
printf("\n");
}
for(int i=0;i<=5;i++)
{
a=a-2;
for(int j=0;j<=i;j++){printf(" ");}
for(int k=a;k>0 ;k--){printf("%d",4-i);}
printf("\n");
}
getche();
}

CALCULATOR (with 'case switch')

#include
#include
void main(void)
{
int a,b;
char c,r;
do{
clrscr();
printf("\nEnter \"Digit Operator Digit \" to perform calculation\t");
scanf("%d %c %d",&a,&c,&b);
switch(c){
case'+':printf("\n%d %c %d = %d",a,c,b,a+b);break;
case'-':printf("\n%d %c %d = %d",a,c,b,a-b);break;
case'*':printf("\n%d %c %d = %d",a,c,b,a*b);break;
case'/':printf("\n%d %c %d = %d",a,c,b,a/b);break;
default:printf("\n>>>>You typed a wrong operator");}
printf("\n\nWant to perform another calculation\t");
r=getche();
}while(r=='y');
getche();
}
 
CALCULATOR (with 'else if')

 
#include
#include
void main(void)
{
int a,b;
char c,r;
do{
clrscr();
printf("\nEnter \"Digit Operator Digit \" to perform calculation\t");
scanf("%d%c%d",&a,&c,&b);
if(c=='+'){printf("\n%d %c %d = %d",a,c,b,a+b);}
else if(c=='-'){printf("\n%d %c %d = %d",a,c,b,a-b);}
else if(c=='*'){printf("\n%d %c %d = %d",a,c,b,a*b);}
else if(c=='/'){printf("\n%d %c %d = %d",a,c,b,a/b);}
else {printf("\n>>>>You typed a wrong operator");}
printf("\n\nWant to perform another calculation\t");
r=getche();
}while(r=='y');
getche();
}

Any Table with range option

#include
#include
void main(void)
{
int a,b,c; clrscr();
printf("Enter the table u want\t"); scanf("%d",&a);
printf("\nEnter the initial range point\t"); scanf("%d",&b);
printf("\nEnter the final range point\t"); scanf("%d",&c);
for(int i=b;i<=c;i++){printf("\n\n\t>>> %d*%d=%d <<<\n",a,i,a*i);}
getche();
} 

Fabonnaci series

 #include
#include
void main(void)
{
int k,a=0,b=1,c;
clrscr();

for(k=0;k<=15;k++)
{
printf("%d\t",a+b);
c=b;
b=a+b;
a=c;
}
getche();
}