void input(char str[]){
 gets(str);
}

void display(char str[]){
 int i;
 for(i=0;str[i]!='\0';i++)
  printf("%c ",str[i]);
 printf("\n");
}

int countA(char str[]){
 int i,count=0;
 for(i=0;str[i]!='\0';i++){
  if(str[i]=='a'||str[i]=='A')
   count++;
 }
 return count;
}

int findItem(char array[],int size,char item){
 int i,found=0;
 for(i=0;array[i]!='\0';i++){
  if(array[i]==item){
   found=1;
   break;
  }
 }
 return found;
}

int isPalindrome(char str1[]){
 int i,size=strlen(str1)-1;
 int yes=1;
 for(i=0,j=size-1;i<=size/2;i++,j--){
  if(str1[i]!=str1[j]){
   yes=0;
   break;
  }
 }
 return yes;
}

int countVowel(char str[]){
 int i,count=0;
 for(i=0;str[i]!='\0';i++){
  //val=toupper(str[i]);
  //if(val=='A'||val=='E'||val=='I'||val=='O'||val=='U')
  if(str[i]=='a'||str[i]=='A'||str[i]=='e'||str[i]=='E'
||str[i]=='i'||str[i]=='I'||str[i]=='o'||str[i]=='O'||str[i]=='u'||str[i]=='U')
   count++;
 }
 return count;
}

MAIN CODE
#include<stdio.h>
#include"strings.h"

int main(void){
 char string1[30]="hello world";
 input(string1);
 display(string1);
 printf("%d\n",countA(string1));
 return 0;
}

void createArray(int la[], int n){
  int i, d;
  for (i=0;i<n;i++){
   if(i<1)
    scanf("%d", &la[i]);
   
   else{
    scanf("%d", &la[i]);
    for(d=1;d<i+1;d++){
     if(la[i]==la[i-d]){
     printf("The number you entered is already in the list. Enter another no.: ");
     i--;}} 
   }
  }
}


void printArray(int la[],int n){
  
 int i;
 for (i=0;i<n;i++){
  printf("%d ", la[i]);
 }
}


int inserAtPos(int la[], int n, int item, int k){
 int i, w,c;
 for(i=1;i>0;i++){
  if(contains(la,item,n)==1){
   printf("The number you want to insert is already in the list. Enter another no.: ");
    scanf("%d", &item);
  }
 
  else{ 
  
   c=n;
  for(w=k; w<(n+1); w++){
   la[c]=la[c-1];
   c--;
  }
  la[k-1]=item;
  break;
  }
 }
  
 return 1;
}


int contains(int la[], int item, int n){
 int i, found=0;
 for(i=0;i<n;i++){
  if(la[i]==item){
   found=1;
   break;
 }}
 return found;
}


void insertFront(int  la[], int n,int  item ){
 int i, w, c;
 for(i=1;i>0;i++){
  if(contains(la,item,n)==1){
   printf("The number you want to insert is already in the list. Enter another no.: ");
    scanf("%d", &item);
  }
  else{
  c=n;
  for(w=(n+1); w>1; w--){
   la[c]=la[c-1];
   c--;
  }
  la[0]=item;
  break;
  }
 }
}


void removeAtPos(int la[], int n, int index){
 int d, i;
  i=index;
  for(d=(i-1);d<n-1;d++){
   la[index-1]=la[index];
   index++;
  }
}


int removeItem(int la[], int n, int item){
 int d, c, f, remove=1;
 
  if(contains(la,item,n)==0){
   remove=-1;
  }
  else{
  for(d=0;d<n;d++){
   if(item==la[d]){
    c=d;
    for(f=(c);f<n-1;f++){
    la[d]=la[d+1];
    d++;
   }
    break;
   } 
  }}
 return remove;
}


int removeFront(int la[], int n){
 int i;
 for(i=0;i<n;i++){
  la[i]=la[i+1];
 }
 return 1;
}


void locateIndex(int  la[],int n, int item){
 int d, i, g, f;
 while(f=1){
 for(i=0;i<n;i++){
  if(item==la[i])
   g=1;
   f=2;
  }
 if(g==1){
  for(d=0;d<n;d++){
   if(item==la[d]){
    printf("The item is at position %d.", d+1); 
   }
   } 
 break;  
 }
 else{
  printf("Item is not in the list.");
  printf("\nEnter another number: ");
  scanf("%d", &item);
  f=1;
  }}
 }
 

void sortAscending(int la[], int n){
 int i, temp, b;
 for(i=0;i<n;i++){
  for(b=0;b<(n-(i+1));b++){
   if (la[b]>la[b+1]){
    temp=la[b];
    la[b]=la[b+1];
    la[b+1]=temp;
 }}}
 printf("Sorting successful!");
 printf("\nARRAY list in ASCENDING order  : ");
 printArray(la, n);
}


void sortDescending(int la[],int n){
 int i, temp, b;
 for(i=0;i<n;i++){
  for(b=0;b<(n-(i+1));b++){
   if (la[b]<la[b+1]){
    temp=la[b];
    la[b]=la[b+1];
    la[b+1]=temp;
 }}}
 printf("\nARRAY list in DESCENDING order  : ");
 printArray(la, n);
}


void locateItem(int  la[],int n, int item){
 int i;
 
 for(i=0;i<n;i++){
  if(item==la[i]){
   printf("Its in the list!");
    break;
  }
 else{
  printf("Not in the list!");
  break;
  }
 }
}

void box(){

 printf("\n[A] Add");
 printf("\n[B] Subtract");
 printf("\n[C] Multiply");
 printf("\n[D] Divide");
 printf(" ");
 printf("\nEnter what you want to execute: ");

}

void box2(){

 printf("\n");
 printf("\nC - reset values and input again");
 printf("\nY - Continue and apply another operation to the answer");
 printf("\nX - Exit");
 printf("\nEnter you choice: ");

}


float add(float x,float y){
 return x+y;
}

float sub(float x,float y){
 return x-y;
}


float multi(float x,float y){
 return x*y;
}

float dev(float x,float y){
 return x/y;
}

void unionof(int result[], int *count, int set1[], int count1, int set2[], int count2){
 
 int i=0, h=0;
 for(i=0;i<count1;i++){
  result[(*count)++]=set1[i];   
}
 for(h=0;h<count2;h++){
  if(contains(count1, set1, count2, set2[h])==0){
  result[(*count)++]=set2[h];
 }}
}


int contains(int count1, int set1[], int count2, int set2[]){

 int i, found=0;

 for(i=0;i<count1;i++){
   if(set1[i]==set2){
    found=1;
    break;
   } 
 }
 return found;
}

void display(int result[],int count){
 int i;
 printf("{");
 for(i=0;i<count;i++)
  printf("%d,",result[i]);
 printf("\b}\n");
}

void toOctal(int num){

 int i, temp, temp2, q, ar[100], count=0, h;

 for (i=0;num>0;i++){
  q=num;
  num=num/8;
  temp=num;
  temp2=temp*8;
  temp=q-temp2;

  count++;
  ar[i]=temp;
 }
 
 for(h=0;h<count;h++){
 printf("%d", ar[count-1-h]);
 }
}

int toDecimal(char *num){

int  b, k, m, n;
  int  len, sum = 0;
 
  len = strlen(num) - 1;
  for(k = 0; k <= len; k++) 
  {
    n = (num[k] - '0');
    if ((n > 8) || (n < 0)) 
    {
      printf("\n\n ERROR! Octal has only 0 to 7!\n");
      return (0);
    }
    for(b = 1, m = len; m > k; m--) 
    {
     b *= 8;
    } 
    sum = sum + n * b;
  }
  return(sum);
}