29. C program to find whether a character is a upper case character or lower case character or special symbol or a number(by using switch case instructions).
#include <stdio.h>

int main(){
char ch;
int val =0;
printf("enter a character: ");
scanf("%c",&ch);
if(ch>= 97 && ch<= 122)
val = 1;
else if(ch>=65 && ch<90)
val = 2;
else if(ch>=33 && ch<= 64 || ch>=91 && ch<=96)
val = 3;
else if(ch >= 48 && ch<=57)
val = 4;
else
val = 0;
switch(val){
case 1:
printf("%c is a lower case alphabet",ch);
break;
case 2:
printf("%c is a upper case alphabet",ch);
break;
case 3:
printf("%c is a special symbol",ch);
break;
case 4:
printf("%c is a numerical digit",ch);
default:
printf("Another character");
}
return 0;
}

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30. C program to find factorial of a given number using Recursion.
#include <stdio.h>

int factorial(int facto){
if (facto == 1 || facto == 0){
return 1;
}
else{
return facto * factorial (facto - 1);
}
}

int main(){
int facto;
printf("enter a number: ");
scanf("%d",&facto);
printf("factorial is %d", factorial (facto));
return 0;
}

31. C program to convert 24 hours clock into AM/PM.
#include <stdio.h>

int main() {
int i;
scanf("%d",&i);
if(i>=13 && i <= 24){
printf ("PM");
}
else{
printf ("AM");
}
return 0;
}

answer would be 'false' causes:
#explanation |Quiz. #4|

as we all know that when we use signed variable of any data type, first compiler will convert
it into unsigned value, proccess to convert signed into unsigned is that:
signed char = -23
1)binary of 23 is (00010111)
2)1's complement of (00010111) this : (11101000)
3)for convert it into unsigned add 1 into (11101000): 11101001 this is the binary of 233
and unsigned value of -23 is 233,
Now!
unsigned int i=23;
signed char c=-23;
if(i>c)
printf("true");
else
printf("false");

::: here we are comparing (23>233) which is false, so final answer would be false.

32. C program to find sum of all even integers between 0 to n.
#include <stdio.h>

int main() {
int n, num2, sum1 = 0;
scanf("%d",&n);
for(int i = 0; i < n; i++){
scanf("%d",&num2);
if(num2 % 2 ==0){
sum1= sum1+num2;
}
else{
continue ;
}
}
printf("%d",sum1);
return 0;
}

33. C program to convert numbers from decimal to binary.
#include <stdio.h>

int main() {
printf("***DECIMAL TO BINARY***\n");
int num ,i=0;
int arr[10];
scanf("%d",&num);
printf ("you have entered %d\nand its binary is: ",num);
while(num>0){
arr[i] = num % 2;
num = num / 2;
i++;

}
for(int j= i-1;j>=0; j--){
printf ("%d ",arr[j]);
}
return 0;
}

34. C program to convert numbers from octal to decimal.
#include <stdio.h>
#include <math.h>

int main()
{
long int Dec=0, Oct;
int up=0;
printf("enter a number: ");
scanf("%ld",&Oct);
while(Oct != 0){
Dec += (Oct %10) * pow(8,up++);
Oct /= 10;
}
printf("res=%ld",Dec);
return 0;
}

35. C program to convert lower case character into upper case character (without using string functions).
#include <stdio.h>

int main()
{
char lower;
int upper;
printf("enter a lower case character: ");
scanf("%c",&lower);
if(lower >=97 && lower<= 122){
upper = lower - 32;
printf("%c",upper);
}
return 0;
}

36. C program to convert upper case character into lower case character (without using string functions).
#include <stdio.h>

int main()
{
int lower;
char upper;
printf("enter a upper case character: ");
scanf("%c",&upper);
if(upper >=65 && upper<= 90){
lower = upper + 32;
printf("%c", lower);
}
return 0;
}

37. Define a structure called VTUstudents , it comprise the fields: VTU No, Name, Branch of Study and Gender. Use array of structures for storing such records randomly. Design and develop a C program for clustering the records based on branch of study and gender (passing arrays aa argument).
#include <stdio.h>
#include <string.h>

struct vtu{
char sName[15];
char sBranch[4];
char sGender[15];
int vtu;
};

//struct vtu st;
void student(char name[15], char br[3], char gen[15], int vtu, int n){
struct vtu st;
int i;
char gender[10], branch[4];
printf("The rcords of vtu are: \n");
for(i=0; i<n; i++){
printf("%d\n", vtu);
printf("%s\n", name);
printf("%s\n", br);
printf("%s\n", gen);
}

printf("enter the gender to be printed: ");
scanf("%s", gender);
for(i=0; i<n; i++){
if(strcmp(gen, gender) == 0){
printf("%d\n", vtu);
printf("%s\n", name);
printf("%s\n", br);
printf("%s\n", gen);
}
}
printf("enter the branch to be printd: \n");
scanf("%s", branch);
for(i=0; i<n; i++){
if(strcmp(br, branch) == 0){
printf("%d\n",vtu);
printf("%s\n", name);
printf("%s\n", br);
printf("%s\n", gen);
}
}
}

int main()
{

struct vtu st[10];
int i,n;
// char gender[10], branch[4];
printf("Enter the number of records: ");
scanf("%d", &n);
for(i =0; i<n; i++){
printf("Enter details of student for record %d\n", i+1);
printf("enter vtu number: ");
scanf("%d", &st[i].vtu);
printf("enter name: ");
scanf("%s", st[i].sName);
printf("enter branch: ");
scanf("%s", st[i].sBranch);
printf("enter gemder: ");
scanf("%s", st[i].sGender);
student( st[i].sName, st[i].sBranch, st[i].sGender, st[i].vtu, n);
}
return 0;
}

38. C program to remove alphabets from a string.
#include <stdio.h>
#include <string.h>

int main()
{
int i=0, j=0, length;
char str[100];
printf("Enter a string with spacial symbols or numbers: ");
gets(str);
length = (int) strlen(str);
while(i != length){
if(str[i] >= 33 && str[i] <= 64)
str[j++] = str[i];
i++;
}
str[j]=0;
printf("string is %s", str);
return 0;
}

39. C program to remove whitespace from a string.
#include <stdio.h>
#include <string.h>

int main()
{
int i=0, j=0, length;
char str[100];
printf("Enter a string with whitespaces: ");
gets(str);
length = (int) strlen(str);
while(i != length){
if(str[i] != ' ')
str[j++] = str[i];
i++;
}
str[j]=0;
printf("string is %s", str);
return 0;
}