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;
}

40. C program to check whether a number is prime number or not a prime number.
#include<stdio.h>

int main(){
int num,prime=0;
printf ("enter a number: ");
scanf("%d",&num);
for(int i=2; i<= num/2; i++){
if(num % i == 0){
prime =1;
break;
}
}
if(num==1){
printf ("prime");
}
else {
if(prime == 1){
printf ("%d is not a prime number",num);
}
else{
printf ("%d is a prime number");
}
}
return 0;
}

41. C program to remove HTML tags from a given string.
#include <stdio.h>
#include <string.h>

void remove_tags(char* str){
int i, in, index=0;
for(i=0;i < strlen(str);i++)
{
if(str[i]=='<'){
in=1;
continue;
}
else if(str[i]=='>'){
in=0;
continue;
}
if(in==0){
str[index]=str[i];
index++;
}
}
str[index]='\0';
};

int main()
{
char str[400];
printf("Enter a string with html tags: ");
gets(str);
printf("you have entered: %s\n", str);
remove_tags(str);
printf("\nnow the nes string is :\n %s",str);

return 0;
}
When input: <h1> I am heading</h1>
Output will be: I am heading

42. C program to calculate the distance between two points (√(x2-x1)^2 + (y2-y1)^2).

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

int main()
{
double x1, x2;
double y1,y2;
double p = 2.0;
double dist;
printf("Enter the value of x1: ");
scanf("%lf", &x1);
printf("Enter the value of y1: ");
scanf("%lf", &y1);

printf("Enter the value of x2: ");
scanf("%lf", &x2);
printf("Enter the value of y2: ");
scanf("%lf", &y2);

double d1, d2;
d1 = x2 -x1;
d2 = y2-y1;
dist = pow(d1,p) + pow(d2,p);
printf("distance between (x1,y1) and (x2, y2) is: %.2lf sqr unit", sqrt(dist));
return 0;
}

43. C program to multiplication of two numbers without using '*' operator.
#include <stdio.h>

int mult(int a, int b){
int res=0;
while(b != 0){
res = res + a;
b--;
}
return res;
}
int main()
{
printf("multiplication = %d", mult(9,4));
return 0;
}

44. C program to add two numbers without using '+' operator.
#include <stdio.h>

int add(int a, int b){
int carry=0;
while(b != 0){
carry = a & b;
a = a ^ b;
b= carry <<1;
}
return a;
}
int main()
{
printf("additon = %d", add(4,4));
return 0;
}

45. C program for subtract two numbers without using '-' operator.
#include <stdio.h>

int sub(int a, int b){
int sb=0;
sb = a + ~b +1;
return sb;
}
int main()
{
printf("subtraction = %d", sub(9,4));
return 0;
}

46. C program for count number of digits.
#include<stdio.h>

int main()
{
int n;
int var=0;
printf("enter a sequence of numbers: ");
scanf("%d",&n);
while(n != 0){
var++;
n /= 10;
}
printf("%d",var);
return 0;
}

Counting digits using recursion:-
#include<stdio.h>

int seq(int n)
{
int ret=0;
while(n != 0){
ret++;
n = n/10;

seq(n);
}
return ret;
}

int main()
{
int n;
int var=0;
printf("enter a sequence of numbers: ");
scanf("%d",&n);
printf("%d", seq(n));
return 0;
}

#Explanation |Quiz. #5|
The correct option is 82 because when a number starts from 0, it is considered as octal number, the octal value of 0110 is 82 ((0*8^3 + 1*8^2 + 1*8^1 + 0*8^0) + 10).

#pattern's
47. C program to print this pattern :-
* *
* *
*
* *
* *
* *
* *
*
* *
* *
* *
* *
*
* *
* *
* *
* *
*
* *
* *
* *
* *
*
* *
* *
______
#include <stdio.h>

int main()
{
for(int k=1; k<=5; k++){
for(int i=1; i<=5; i++){
for(int j=1; j<=5; j++){
if(j>=6-i && j<=6-i || i*i == j*j){
printf("*");

}
else{
printf(" ");
}
}
printf("\n");
}

}
return 0;
}

48. C program to sum of entered digit's (using recursion).
#include <stdio.h>

int sum(int n){
int s;
if(n <= 0){
return 0;
}
else{
return n%10 + sum(n/10);
}
}
int main()
{
printf("Enter some numbers in sequence: ");
int n;
scanf("%d", &n);
int res = sum(n);
printf("sum of these all numbers is: %d ", res);
return 0;
}

#DSA_Series
49. C Program to insert an element in array on the given index.
#include <stdio.h>

void display(int *arr, int size){
for(int i=0; i<=size; i++){
printf("%d ", arr[i]);
}
printf("\n");
}
int insert_arr(int *arr, int val, int size, int capacity, int ind){
if(size>capacity){
printf("Overflow!");
return -1;
}
else{
for(int i=size; i>=ind-1; i--){
arr[i+1] = arr[i];
}
arr[ind] = val;
return 1;
}
}

int main()
{
int arr[100] = {1,2,6,7};
int size = 4, element = 9, index = 1;
printf("Before insertion\n");
display(arr, size);
insert_arr(arr,234, size, 100, index);
size += 1;
printf("After insertion\n");
display(arr, size);

return 0;
}

# Explanation |Quiz. #6|
Here ,ptr is a pointer,and it'll take the address of variable var i.e it'll store 5, then in printf statement, the value will be print first and then would be increment, so the correct answer is 5.